zero Posted June 20, 2015 Share Posted June 20, 2015 I bought a $99 Harbor freight vacuum pump with a 20% off coupon and found a new manifold set on Ebay for $27 with free shipping! In hindsight I would buy better gauges. When I am done with this I will sell them. I do have the luxury of a friend that has a Flea market stand in the winter so will likely break even on them. Jim SW FL That HF pump looks like a great deal. When I bought my vacuum pump - HF did not have them and I paid $200 for a used pump from a pawn shop. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 20, 2015 Author Share Posted June 20, 2015 The cheap set of gauges I bought claims it is for R12 134A and R22. ?? But like Sgt Schultz, I know nothing? Left click to enlarge Quote Link to comment Share on other sites More sharing options...
zero Posted June 20, 2015 Share Posted June 20, 2015 I hate to tell you this now but your MH makes a very good vacuum pump the brake booster line will drop the vacuum to about the same as a pump will even just stuck over the gauge center fitting. I've yet to see a gas engine pull 29"-30" of mercury for vaccum. 15"-20" maybe. The main reason to use a good vacuum pump on the AC system is to lower the boiling point of any trapped moisture to room temperature so it boils out. 15" of vacuum lets water boil at 176 degrees F. 20" of vacuum lets water boil at 160 F. If you are working in a shop with a temp of 75 degrees F - it takes 29" of vacuum at least - to make moisture boil out of the AC system. If the shop is 65 degrees F - it takes even more vacuum. 29" is considered the bare minimum for AC work. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 20, 2015 Author Share Posted June 20, 2015 That HF pump looks like a great deal. When I bought my vacuum pump - HF did not have them and I paid $200 for a used pump form a pawn shop. Your pump is likely much higher quality? Jim Quote Link to comment Share on other sites More sharing options...
zero Posted June 20, 2015 Share Posted June 20, 2015 Your pump is likely much higher quality? Jim Hey - if the HF pump can pull 29" of vacuum - that's all that counts. I've gotten some great tools from HFalong with some absolute crap. You never know. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 20, 2015 Author Share Posted June 20, 2015 Another thing I have noticed. The old compressor and the receiver/dryer had not a drop of oil in them. I left both upside down turned the compressor and nothing came out. I suspect if I had put a couple cans of refrigerant in and turned it on the compressor would have self destructed? Leaves me wondering if an AC shop would know this?? Jim Quote Link to comment Share on other sites More sharing options...
Back East Don Posted June 20, 2015 Share Posted June 20, 2015 Ok. Give me a few days. Broke down in ND now. See trip report I'm in absolutely no hurry. Please stay safe. Quote Link to comment Share on other sites More sharing options...
Maineah Posted June 20, 2015 Share Posted June 20, 2015 I've yet to see a gas engine pull 29"-30" of mercury for vaccum. 15"-20" maybe. The main reason to use a good vacuum pump on the AC system is to lower the boiling point of any trapped moisture to room temperature so it boils out. 15" of vacuum lets water boil at 176 degrees F. 20" of vacuum lets water boil at 160 F. If you are working in a shop with a temp of 75 degrees F - it takes 29" of vacuum at least - to make moisture boil out of the AC system. If the shop is 65 degrees F - it takes even more vacuum. 29" is considered the bare minimum for AC work. I was born a razed in the south AC was not so much a luxury as it was a necessity my first taste of AC work was in 1963. Most AC systems do not have enough water in them to need to reduce the system to promote boiling they do however need to be dried primarily of ambient moisture vacuum is capable of that. Now the project has gone beyond that it is now figured in microns not inches of mercury this is way beyond the realm of a backyard mechanic both in time and money. You can think as you wish but for most jobs the 20” an engine will pull (my 4 liter Tacoma will do that) is sufficient to dry most systems anything left is covered by the dryer. If you want to get into the realm of deep vacuum you had better have a pocket full of money no cheap pump or cheap gauge seals will do this. A 20 + year old system is not rocket science if you do the best you can chances are pretty high it’s going to work and work well. If you don’t own a pump or don’t want to buy one to use once the engine will suffice. Enjoy being able to work on the systems while you can high pressure systems are already out there. Quote Link to comment Share on other sites More sharing options...
Maineah Posted June 20, 2015 Share Posted June 20, 2015 Another thing I have noticed. The old compressor and the receiver/dryer had not a drop of oil in them. I left both upside down turned the compressor and nothing came out. I suspect if I had put a couple cans of refrigerant in and turned it on the compressor would have self destructed? Leaves me wondering if an AC shop would know this?? Jim It's probably in the dryer. Quote Link to comment Share on other sites More sharing options...
Back East Don Posted June 21, 2015 Share Posted June 21, 2015 I was born a razed in the south AC was not so much a luxury as it was a necessity my first taste of AC work was in 1963. Most AC systems do not have enough water in them to need to reduce the system to promote boiling they do however need to be dried primarily of ambient moisture vacuum is capable of that. Now the project has gone beyond that it is now figured in microns not inches of mercury this is way beyond the realm of a backyard mechanic both in time and money. You can think as you wish but for most jobs the 20” an engine will pull (my 4 liter Tacoma will do that) is sufficient to dry most systems anything left is covered by the dryer. If you want to get into the realm of deep vacuum you had better have a pocket full of money no cheap pump or cheap gauge seals will do this. A 20 + year old system is not rocket science if you do the best you can chances are pretty high it’s going to work and work well. If you don’t own a pump or don’t want to buy one to use once the engine will suffice. Enjoy being able to work on the systems while you can high pressure systems are already out there. So your saying I don't need to borrow that Stokes Microvac 150CFM 10 millitorr pump to work on my AC? Good, cause the thing is nearly half a ton and I'm already having trouble finding adapters. How's tourist season treating you? Wish I was up in Saco this weekend or anywhere other than being stuck here at home contemplating more work. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 21, 2015 Author Share Posted June 21, 2015 It's probably in the dryer. According to the manual there is suppose to be 7oz of oil in the system. With the compressor and receiver/dryer turned upside down shouldn't I be getting some oil dripping out?? Jim Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 28, 2015 Author Share Posted June 28, 2015 Here it is a couple weeks later and I have almost all my ducks in a row. My usual frantic pace of stopped. I was doing OK till I ordered a part fromAmazon and they decided to ship it after 2 phone call and trying to cancel the order, 5 days to ship it. After much research and question asking I think I am comfortable with putting this back together and charging it. Questions come up, probably silly ones to people in the know. Like add oil to the compressor, OK simple enough, which hole? There are 2 holes in the compressor, some say large vacuum hole, some say it does not matter. Color me confused, so I will add to the large vacuum hole. That is where the oil would go if I used an inline injector. I have one thing left to borrow and that is a refrigerant scale and I have a friend that has one. If he can find it. I was off to buy the last item, which would be double end capped PAG 46 oil and nobody local carries it. I think they do carry it but they call it everything but double end capped, they use words like delux, priemium, moister resistant, but do not say double end capped. The guys at NAPA never heard of it. To make sure I get this right I ordered online and will have to wait till Thursday for delivery. So my original joking guess of 4 to 6 weeks may not be that far off. Jim SW FL Quote Link to comment Share on other sites More sharing options...
WME Posted June 29, 2015 Share Posted June 29, 2015 Ah "The best laid plans of mice and men....." Quote Link to comment Share on other sites More sharing options...
zero Posted June 29, 2015 Share Posted June 29, 2015 Most AC systems do not have enough water in them to need to reduce the system to promote boiling they do however need to be dried primarily of ambient moisture vacuum is capable of that. If you want to get into the realm of deep vacuum you had better have a pocket full of money no cheap pump or cheap gauge seals will do this. I cannot say I have comprehensive knowledge of "most systems." Just a guess but probably "most" systems work and this discussion is moot. For those that do NOT work and have been opened up to the air - moisture can be a killer to the system. Especially if ice-chips develop internally. I've been to two AC service schools and can't say any of what I was taught coincides with what you are saying. The main reason for pulling a good vacuum is to make any trapped moisture boil at room temp. No natural engine vacuum can do that. As to a pump being too expensive?? Oh come on ! A $20 venturi pump from Harbor Freight will pull 28.3 " of mercury @ sea-level. Not so great if you live a mile high in Colorado though. A $99 electric pump from Harbor Freight will pull a 29.9" vacuum (10 Pascals). Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 30, 2015 Author Share Posted June 30, 2015 So I start wondering, how do I know this PAG oil is double end capped? Other than a couple advertising statements?? One thing leads to another and I send an email off to a retailer of the product. Expiring minds need to know. His response is "it is just a regular cap, you take it off and there is a paper seal under it" Oh poopies! The double end capped is not new it has been around as near as I can tell since 2004. Most of what is sold in parts stores does not appear to be double end capped. But most are not forthcoming with that info. Jim SW FL Quote Link to comment Share on other sites More sharing options...
zero Posted June 30, 2015 Share Posted June 30, 2015 Why not just use the time-proven ester oil and eliminate any question of compatability? Quote Link to comment Share on other sites More sharing options...
WME Posted June 30, 2015 Share Posted June 30, 2015 I'm in absolutely no hurry. Please stay safe. OK back home and the RV has been turn around and is ready for the next adventure. I found the R12 gauges, you still interested? Quote Link to comment Share on other sites More sharing options...
Back East Don Posted June 30, 2015 Share Posted June 30, 2015 Sure, just let me know how much and how to get the money to you. Mine went into the shop today. First time someone other than me is working on it since I've had it. Having the transmission fluid changed and the tail piece bushing and seal done. A very interesting story regarding the shop I took it too and the conversation about the RV with the owner of the shop. First, I love an office with a drum kit and guitar in it, makes me feel right at home. PM me the info. Again, no hurry as this is on the slow burner. Got tons of irons in the fire right now and this project will wait. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 30, 2015 Author Share Posted June 30, 2015 Why not just use the time-proven ester oil and eliminate any question of compatability? When being a guinea pig and off into unknown areas one has to read between the lines. I ended up replacing everything in my system which was not the original plan, except the solid tubing, which I have flushed and reflushed and then flushed again, so compatibility is no longer an issue. There are many articles and threads over Ester, mineral and PAG, there are charts and graphs and discussions ad nauseum. But the people who are doing the warrantying are using PAG oil. Double end capped is the superior PAG so that is what I want to use. If I were starting again I would look into parts for later years that were specifically designed for 134A. Jim SW FL Quote Link to comment Share on other sites More sharing options...
zero Posted June 30, 2015 Share Posted June 30, 2015 When being a guinea pig and off into unknown areas one has to read between the lines. I ended up replacing everything in my system which was not the original plan, except the solid tubing, which I have flushed and reflushed and then flushed again, so compatibility is no longer an issue. There are many articles and threads over Ester, mineral and PAG, there are charts and graphs and discussions ad nauseum. But the people who are doing the warrantying are using PAG oil. Double end capped is the superior PAG so that is what I want to use. If I were starting again I would look into parts for later years that were specifically designed for 134A. Jim SW FL From the specs I've read - the 'double" PAG certainly seems the best. But I'm a bit skeptical. As to warrantees - do any shops warrarnty R12 to 134A conversions? I know the shop I worked for didn't (Chevy dealership). Quote Link to comment Share on other sites More sharing options...
jjrbus Posted June 30, 2015 Author Share Posted June 30, 2015 I was referring to new car manufacturers warranty's. Jim SW FL Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 2, 2015 Author Share Posted July 2, 2015 The AC adventure continues. As usual I start each job with the great lie "I don't have to write that down or take a picture, I'll remember" I don't write as much as I used to but I do take a lot of pictures. My purchase included a gasket kit which included all gaskets I would need except for the one for the pressure switch. So off the auto parts place to get one gasket but had to buy a $5 kit to get the one I needed. Situation normal, I enjoy running around looking for stuff and spending extra money. More fun than golf anyway. As I am assembling things which would be an easy job for a pygmy contortionist I noticed that the power wire for the clutch was too short. Would have been an easy fix on the bench. But I guess jamming myself under the hood trying to splice wires is good exercise. Then I discover that the bottom bolts will not go in with the compressor in place, so have to wiggle and push and twist to get them in. Where is that pygmy contortionist when you need her? The Denso compressor comes preloaded with 5oz of PAG46, there is a sticker right on it saying so. The AC guys insist on dumping what is in there and installing fresh. I measured it as I drained it, 3 1/2oz. I twisted turned, rotated, 3 1/2oz that is all that was in there, I would expect better from Denso!! Glad I listened. I hoped to be able to put a vacuum on it today, but it started to rain, I can work in a little rain, but this is the lightning capital of the US and it sends me scurrying inside. Jim SW FL Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 3, 2015 Author Share Posted July 3, 2015 So far it has been a good day, not one trip to the auto parts store, wonder if they miss me? As I was cleaning up I found an extra electrical fitting that came with the compressor I could have saved myself a bit of work had I noticed it before. Bolting the compressor back in is difficult at best, I have no idea how I got the one bolt out when I started? In hindsight I would pull the power steering pump. This V6 leaves no room to spare, inner fenders really need to go! My harbor freight vacuum pump and $25 gauge set, hopefully they are accurate? I think doing again I would spend more on the gauges and get a quality set. There is some fastening to do and more to install but I buckled up the AC system as fast as I could and got it under vacuum, to avoid moisture buildup. As suggested I vacuumed for about 5 minutes then shut valves and let set for 20 minutes and lost no vacuum, yipee Now I will evacuate this for about an hour and then leave set overnight and recheck as suggested on AC forum. IF it lasts overnight I will reinstall engine parts and then try to charge with 134A >>>>>>>>>>>>>>>>>>>> If it starts?? Jim SW FL Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 4, 2015 Author Share Posted July 4, 2015 My elation was short lived, this morning I had lost all vacuum. Suspecting the elcheapo manifold set, I tested as best I could and it very slowly leaks down. But I am hampered it's a Holiday and the wife expects to be catered to, so this goes on hold for a couple days. Jim Quote Link to comment Share on other sites More sharing options...
WME Posted July 4, 2015 Share Posted July 4, 2015 Pull a vacuum, remove gauge, after 24 hr install gauge and see what's left. Quote Link to comment Share on other sites More sharing options...
zero Posted July 5, 2015 Share Posted July 5, 2015 My elation was short lived, this morning I had lost all vacuum. Suspecting the elcheapo manifold set, I tested as best I could and it very slowly leaks down. But I am hampered it's a Holiday and the wife expects to be catered to, so this goes on hold for a couple days. Jim That is more the "norm" then the exception when working on older AC systems. But yes - with your's - you changed a lot of parts. I would pressure test it before I vacuum tested it again. Pressure testing often saves time and wasted refrigerant. Get yourself a cheap low-port fitting (or high-port) and get an air-chuck hooked to it so you can hook an air-compressor to your AC system. Then feed it 120 PSI (or less if you have a regulator) - and check everywhere with soapy water. Hard to find leaks will often show this way that can't even be found with infrared dye. THIS is very easy to do. You might just have a hose leaking and this willl show it fast. I know the AC books always talk about pulling a vacuum but . . I've had a few that held full vacuum for a week and still leaked when I charged the system. I've had many that showed no leaks when charged and running - but once you shut the system off and the low and high sides "equalize" - leaks can start to show up. Like I said, pressure testing has saved me time often and unlike a vacuum test - you can spray with soapy water and check for leaks. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 5, 2015 Author Share Posted July 5, 2015 Tried removing and reinstalling gauge, not doing well with that. I have toyed with the gauge and managed to get it to hold vacuum for 30 minutes. The AC guys seem to think this is enough to go ahead and charge. Pressurizing the system sounds like a great idea, but I have an old compressor with no filters and would be afraid of contaminating system with oil, water and who knows what else. I will put in radiator, fan, belts and such and maybe come up with another option? Thanks for the input always appreciated. Jim SW FL Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 11, 2015 Author Share Posted July 11, 2015 Went to AutoZone and rented AC manifold and my system is borderline. It will hold a vacuum for 30 minutes, about at an hour will be at 26 on the 0-30 scale.. Ac guys are saying charge. But being the way i am I would like to test it further. I have no gas available except acetylene and have looked around and can find no inert gas for small money except for this. I am wondering if adapting this to my purpose would be feasible/practical? I can't really add any more as I have no ideas yet, so any input, thoughts, ideas or suggestions would be appreciated. Quote Link to comment Share on other sites More sharing options...
zero Posted July 11, 2015 Share Posted July 11, 2015 I have toyed with the gauge and managed to get it to hold vacuum for 30 minutes. The AC guys seem to think this is enough to go ahead and charge. Thanks for the input always appreciated. Jim SW FL If any "AC guy" told you to it's OK to charge with a leak like that, I don't think he knows his a*s from a hole in the ground. A sound system will hold a vacuum for days, weeks, etc. without going down at all. And even when a system will hold a vacuum with NO loss for a week - it still might leak when charged. 29" of vacuum is not the same as 150 PSI of pressure that happens when the AC is working. That's why I always pressure check mine with soapy water. Saves a lot of wasted refrigerant and recharges. Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 27, 2015 Author Share Posted July 27, 2015 Here it is another couple weeks goes by. I managed to rent a nitrogen tank and gauges for a case of Coor's lite, I may give him 2? Pressurized system and soap tested everything and no leaks, so only leaves the evaporator area. Of course it is there, it is the hardest thing to get to! Pull evaporator and hook back up without case, pressurize and one of the few things I did not replace is bubbling away!! The pressure switch, not on the threaded side on the electrical connection side. I keep humming Don Ho, tiny bubbles in my wine, makes me unhappy, I don't feel fine : ) A quick web search shows the pressure switch is not a popular item the only place I can find it online is at Oreillys. Murray Climate Control - Compressor Cut-Off Switch Part # 35829Not sure if the pressures are right? for 134A? Not able to cross reference so not even sure if it is the right switch? On Pressure (psi): 30/304 psi Off Pressure (psi): 29/391 ps http://www.oreillyauto.com/site/c/detail/MRY0/35829/01961.oap?year=1993&make=Toyota&model=Pickup&vi=1277995&ck=Search_a!s!c+compressor+cutoff+switch_1277995_4918&keyword=a!s!c+compressor+cutoff+switch Jim SW FL Quote Link to comment Share on other sites More sharing options...
WME Posted July 28, 2015 Share Posted July 28, 2015 Doesn't look good... The dates for most of the Toyotas are pre r-134a Quote Link to comment Share on other sites More sharing options...
jjrbus Posted July 28, 2015 Author Share Posted July 28, 2015 Thanks for the response. I found this, 94 should have been 134A? is product fits the following 1993 Toyota Pickup Base 6 Cyl 3.0L 1988-1994: All Submodels; All Engines; Murray and Four Seasons, show same part. Quote Link to comment Share on other sites More sharing options...
WME Posted July 28, 2015 Share Posted July 28, 2015 93-94 were the switch over years, try looking for the pressure switch for a 95. If there is a parts drawing on the 88-94 sensor look at the compressor fittings. R-12 and R134 are different. Quote Link to comment Share on other sites More sharing options...
snail powered Posted July 28, 2015 Share Posted July 28, 2015 If you can find a copy of the user's manual for your year and model of truck it will should give you the numbers you need to know for type of fluids and for the pressures. Quote Link to comment Share on other sites More sharing options...
WME Posted July 28, 2015 Share Posted July 28, 2015 Ya'll know we maybe overthinkin this, if the sensor didn't leak you would have gone on your merry way and filled the system with oil and r-134. Maybe just replace it with the same and press on. Quote Link to comment Share on other sites More sharing options...
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