cjac Posted June 4, 2017 Share Posted June 4, 2017 After redoing my brake system my brakes feels spongy . This is what I've done. New master cylinder, new brake booster, new brake hoses, new pads, new shoes, new wheel cylinders, new brake fluid and bleed all the air out . The only thing that an't new is the calibers. My brake petal is about even with my gas petal before I feel resistance. This may be normal since I been driving my rig with a bad brake booster. Any thoughts would be appreciated. Thanks Quote Link to comment Share on other sites More sharing options...
linda s Posted June 4, 2017 Share Posted June 4, 2017 Did you preload the master cylinder with fluid before install, did you start the bleed at the last line on the system, rear drivers side. Also air can get trapped in the proportioning valve. Happened to me on my Nissan . Best fix for that is a pressure bleed but that would require taking it to a shop. Also possible you just didn't get it quite right. It happens. To me spongy always means air somewhere Linda S Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted June 7, 2017 Share Posted June 7, 2017 I would get a couple of big bottles of brake fluid, get a helper and start bleeding. The bleeding sequence and technique does make a difference. Googling "brake bleed sequence 93 toyota pickup" and scroll down you will see diagrams of the recommended sequence FL,FR,RR,RL. Not sure how that applies to our toys or when to do the proportion valve. Last time I did mine I started at the back and worked forward - used a full 32oz bottle of brake fluid. I use the "pump the air out" technique. If I still had spongy after that, I would look for some sort of leak somewhere. BTW< if you did not prime your master cylinder, expect problems there. Quote Link to comment Share on other sites More sharing options...
cjac Posted June 8, 2017 Author Share Posted June 8, 2017 I preloaded the master cylinder and started bleeding from the LR RR RF LF but I didn't do the proportioning valve . I bought new master cylinder for the year of my rig (1984) but changed over to the 1 Ton rearend and the front end . Are the master cylinders all the same or different between the 1/2 and the 1 Ton models? Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted June 9, 2017 Share Posted June 9, 2017 I doubt having the "wrong" master cylinder would cause mushiness. After it is all bled, too small of a master might cause other issues though, What technique are using? (to bleed) Quote Link to comment Share on other sites More sharing options...
cjac Posted June 11, 2017 Author Share Posted June 11, 2017 I adjusted the rear brake shoes and my brake pedal is Alot better. Will try to bleed again to make sure all the air is out . I will do the proportioning valve first than the LR RR RF LF . I was told that if you take a bottle of brake fluid put a hose in the bottle and connect to the bleeder valve with it open and pump the brake slowly will get the air out , do this to each wheel. Has anyone heard of this ? Quote Link to comment Share on other sites More sharing options...
Derek up North Posted June 11, 2017 Share Posted June 11, 2017 42 minutes ago, cjac said: ... pump the brake slowly will get the air out ... That's the way I've always done it, EXCEPT that after each 'down' of the pedal, you have to close the bleeder otherwise what your last pump has displaced simply gets sucked beck up the hose again. Makes it a 2 person job, unless you use the 'trick' I've also used for decades. Will explain in the morning. Off to bed now. Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted June 12, 2017 Share Posted June 12, 2017 I use the pump it out method. Helper pumps pedal and holds, I open bleed valve and pedal goes to floor. Helper holds it there with a verbal signal "floor". I close valve and yell "pedal" and the helper repeats. Get a piece of clear tubing and a clear jar - when the bubbles clear and the fluid is clean looking, move on to the wheel. Also check master cylinder every 6-8 cycles and top off brake fluid (otherwise when it goes dry you get to start all over). I changed my fluid last year - brake fluid does absorb water and if neglected it can cause internal rusting. I say about every 5 years is reasonable. I used a quart of fluid. Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted June 13, 2017 Share Posted June 13, 2017 (edited) I go with the "bleed it again" folks. Since I have to do a lot of bleeding by myself I use one of these handy "Motion Pro" one man bleeders. For $11.69 it has more than paid for itself. When you are back under the rear axle yelling "Pedal Up/Pedal Down" while your wife says "WHAT?" and you just sucked some air back into the system (again) $11.69 is real cheap marriage insurance. https://www.amazon.com/Motion-Pro-08-0143-Hydraulic-Bleeder/dp/B000MXW2EM I also use pure Dot 5 silicone fluid in everything since I live 2 miles from the ocean and water is always in the air. The silicone won't adsorb water. It is very purple and you can bleed it to your hearts content. Put the old fluid in a clear glass jar and the good stuff (purple) floats over the bad stuff (not purple), so you can strain and reuse the good stuff. Dot 5 costs more but does not have to be changed every year or so. The other thing with a new master cylinder (besides the primeing) is to adjust the plunger length. The plunger is the rod in the unit that pushes the cup in the back of the cylinder of the master. It is adjustable with a nut on the rod. I just did my truck and it now has a little more play before it engages, but is firm when it does. I think the book says to bleed from the furthest wheel to the closest wheel (from the Master). I am not sure if the proportioner valve has a bleeder, I don't think it does? see diagram at link Toyota FSM-LSP&BV.pdf Edited June 13, 2017 by Lee & Joan add link Quote Link to comment Share on other sites More sharing options...
cjac Posted June 17, 2017 Author Share Posted June 17, 2017 Purple dot 5 brake fluid what brand is and can you post a pic of the container Quote Link to comment Share on other sites More sharing options...
DanAatTheCape Posted June 18, 2017 Share Posted June 18, 2017 I use DOT III. Also, if they can not be bled properly. take a good look at you front brake assemblies and make sure the bleed valves are at the top - it is possible to switch the two sides (if they were completely removed during job). If installed on wrong side, the bleed valve will be at the bottom and all the air will not be removed even with extensive bleeding. this is what I use: https://www.walmart.com/ip/Prestone-DOT-3-Brake-Fluid-32-oz/35764364 Quote Link to comment Share on other sites More sharing options...
fred heath Posted June 18, 2017 Share Posted June 18, 2017 My hydraulic system (including clutch) uses DOT 5 Silicone. The bottle will be labeled with this number. It is pricy, but doesn't absorb water. BUT REMEMBER!!!!!!!! The entire system needs to be flushed of any old brake fluid before adding the DOT 5. The two fluids will not mix. Quote Link to comment Share on other sites More sharing options...
Derek up North Posted June 18, 2017 Share Posted June 18, 2017 DOT 5 (Silicone based), NOT to be confused with DOT 5.1 (glycol based). Quote Link to comment Share on other sites More sharing options...
Lee & Joan Posted June 20, 2017 Share Posted June 20, 2017 http://forums.mtbr.com/brake-time/silicone-based-dot5-busting-myth-832808.html I just searched the web for the best price on DOT 5 so I have used different brands over the years. I think I read somewhere that there really is no difference in brands of DOT 5 so let low price dictate your brand. I have not had any problems flushing out the old glycol fluid, I just add the Purple DOT 5 to the reservoir and pump it through. You see the gucky old glycol come out the bleeder as clear or brown yellow, then a transition to mild purple, them finally a full on deep purple. I have then let all the pumped out fluid sit in a clear glass jar for a day. All the still good purple DOT5 rises to the top and the old gunge sinks to the bottom. Decant the dark purple DOT5 off the top through a coffee filter and "WHA LA" you can reclaim the extra DOT 5 you used to pump all the bubbles and crud out of the system. That makes it less expensive to do a really "overkill" job on purging the old fluid out. When you look at the cost of changing your Glycol fluid every year or so, or not changing it and getting corrosion, leaky seals and stuck cylinders, well DOT 5 is way cheaper... Some say that DOT5 has less heat tolerance, but that is only true when the fluid is brand new. Conventional fluid starts to lose its heat tolerance once you open the bottle and degrades over time, but DOT5 stay the same for decades. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.