Master Cylinder Rebuild - DIY (2 Viewers)
- Thread starter Skidoo
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Thanks so much! I double checked my fluid level today by doing the 40 pumps and it was right to the max line with the key off. I am going to give the grommets a try as the front one definitely looks like it is weeping a bit. Will I need to do a complete bleed after I remove and replace the reservoir?
It would be best to bleed after. But you may be able to get away without. Time how long booster motor runs before you remove reservoir, after the 40 pump topping procedure. Than time again after grommet installed and reservoir topped. If pre and post are same times and both 30 to 40 sec, you golden. But do check again after some actually use of brakes.
Got some great info from the thread. I ended up purchasing a rebuilt unit from Andy Le after hearing some good reviews.
Ive got a 98 model. Recently replaced the unit. Bled the brakes. Everything worked well for a day. Then i lost 95% of braking power. Fluid returned to the reservoir. The pedal goes all the way to the floor.
During the bleeding process i didnt not activate abs and re-bleed. Could this be the reason for my issue?
Ive got a 98 model. Recently replaced the unit. Bled the brakes. Everything worked well for a day. Then i lost 95% of braking power. Fluid returned to the reservoir. The pedal goes all the way to the floor.
During the bleeding process i didnt not activate abs and re-bleed. Could this be the reason for my issue?
I doubt it. I'm no expert though... Did go through major issues with mine, also a 98 LC however I never lost brake function...
Pretty sure your accumulator or pump motor are no good.
In my 98 I rebuilt the MC, changed pump. Still lost brakes. Turned out to be the accumulator. If that can't hold pressure you lose brakes apparently.
Andy has been pretty helpful. Sending me a different pump. Slowly but surely this puzzel will be solved.
navydivedoc
SILVER Star
Just did this today on my 1999. Excellent write up, and this is a pretty straight forward job. I did replace the grommets on the reservoir, though mine appeared to be in good condition. No evidence of leakage and my electrical connectors as discussed a few pages back were pristine.
Mine had some locktite material on the clevis that made it a challenge to get off the old pushrod. I ended up using a set of vice grips on the threaded rod. No going back at that point. Not a problem as there is a new one, but this thread didn't mention that difficulty.
I could only see some very fine lines/scoring on the o-rings of the old piston. I definitely could feel an improvement after putting everything back together. I did a brake bleed that is probably adequate. But, I have an appointment with the dealer on Tuesday to do a full bleed of the entire system.
About 3 hours taking my time, helped by a buddy. 2 beers, 2
job. I used a total of 2 quarts of brake fluid, including some to rinse out the reservoir after denatured alcohol.
Thanks to the OP and all of the follow up. This really made me confident and saved me huge $$ vs going to the dealer.
EDIT: Did take it to the dealer for a full system bleed and some new dust caps. It felt pretty good before this visit, and I thought I had done a good bleed, but this definitely improved the feel. Worth the money for 100% and peace of mind. Good as new now, ready for another 206k miles.
Mine had some locktite material on the clevis that made it a challenge to get off the old pushrod. I ended up using a set of vice grips on the threaded rod. No going back at that point. Not a problem as there is a new one, but this thread didn't mention that difficulty.
I could only see some very fine lines/scoring on the o-rings of the old piston. I definitely could feel an improvement after putting everything back together. I did a brake bleed that is probably adequate. But, I have an appointment with the dealer on Tuesday to do a full bleed of the entire system.
About 3 hours taking my time, helped by a buddy. 2 beers, 2
job. I used a total of 2 quarts of brake fluid, including some to rinse out the reservoir after denatured alcohol.Thanks to the OP and all of the follow up. This really made me confident and saved me huge $$ vs going to the dealer.
EDIT: Did take it to the dealer for a full system bleed and some new dust caps. It felt pretty good before this visit, and I thought I had done a good bleed, but this definitely improved the feel. Worth the money for 100% and peace of mind. Good as new now, ready for another 206k miles.
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@Skidoo Another thanks from me. I did this job recently and it cured my falling brake pedal. I was unsure of my bleeding work because the Techstream commands seemed to do nothing. I took it to a dealer and they confirmed all was well. I did some dirt road ABS stops and nothing seemed out of the ordinary. It feels really good to have firm brakes on my 06 LX.
The only thing that hung me up was removal of the assembly from the engine bay. When putting it back in, I zip-tied the brake lines out of the way and that made it about 95% easier.
Total job probably took me 6-7 hours. Lots of time bleeding the brakes and a solid hour playing liquid labyrinth with the reservoir trying to get all the gunk out. Doing it again now and having a second person on hand for bleeding I could probably do it in 3-5 hours, but I'd say first timers, count on 6+ hours if you're slow like me.
The only thing that hung me up was removal of the assembly from the engine bay. When putting it back in, I zip-tied the brake lines out of the way and that made it about 95% easier.
Total job probably took me 6-7 hours. Lots of time bleeding the brakes and a solid hour playing liquid labyrinth with the reservoir trying to get all the gunk out. Doing it again now and having a second person on hand for bleeding I could probably do it in 3-5 hours, but I'd say first timers, count on 6+ hours if you're slow like me.
- Thread starter
- #373
You are welcome.
Went through a couple key fobs then grabbed your Titanium Key Fob = Totally bulletproof. Thanks.
Met you at HIH 2017, but have missed HIH since, I have missed going it's a great group.
Has anyone seen something like this before? There appears to be some kind of build-up on the inside of my brake reservoir. I don't really see anyway to clean it out, as the reservoir has several baffles that prevent direct access to clean it up.
The brake fluid that I drained out did look clean, but had particles in it as well.
All of this comes from trying to chase down a screeching sound coming from the hydraulic brake booster. It seems to only happen first thing in the morning (hot or cold days) and then never again for the whole day. Even if I'm an out of the car all day long. I've even triggered the constant beep for several minutes until the pump seems to be able to build up enough pressure.
The motor runs great, and taking apart the motor, it looks almost brand new inside (previous owner did say he had the HBB replaced a couple of years ago). I don't seem to be leaking/losing any fluid.
Other than the build up inside the reservoir, I can't see any obvious issues.
The plan right now is to order a replacement reservoir from the local dealer, then fully flush and bleed the brakes
![20200712_141556[1].jpg](data:image/svg+xml;charset=utf-8,%3Csvg xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg' width='1920' height='1440' viewBox%3D'0 0 1920 1440'%2F%3E "20200712_141556[1].jpg")
The brake fluid that I drained out did look clean, but had particles in it as well.
All of this comes from trying to chase down a screeching sound coming from the hydraulic brake booster. It seems to only happen first thing in the morning (hot or cold days) and then never again for the whole day. Even if I'm an out of the car all day long. I've even triggered the constant beep for several minutes until the pump seems to be able to build up enough pressure.
The motor runs great, and taking apart the motor, it looks almost brand new inside (previous owner did say he had the HBB replaced a couple of years ago). I don't seem to be leaking/losing any fluid.
Other than the build up inside the reservoir, I can't see any obvious issues.
The plan right now is to order a replacement reservoir from the local dealer, then fully flush and bleed the brakes
I have the same screeching issue. Please keep us updated if you find the issue
You can fill with a degreaser like Simple Green at 100% Let it soak overnight. Shaking vigorously ever now and then.Make sure to rinse 100 % of SG out with water and dry 100%. You can not leave any moisture in it. Save the uses Simple Green to clean more stuff like power steering reservoir or engine parts.
But you may be wasting your time. I say this because staining indicates high moisture content, very old fluid that had a lot of gunk buildup. This damages seals. If you have the screeching sound, bubbles coming up front of reservoir with screench and brake alarm. Your master is shot. Nothing you can do but replace it. If it's to the point brake alarm is set off, indicating low pressure. Then your running brake booster motor to long and often. You'll burn up the booster motor. If booster motor fails you loose brakes.
You can just buy the master, which includes reservoir and ABS unit. The booster assembly can be bought with it or separately.
- Thread starter
- #377
My reservoir looked like that, in my post #5 here I mentioned cleaning it, you may have to repeat a couple times but it worked.
Sadly, as of 2018 ish, denatured alcohol is no longer available if the great state of California...
I'll give simple green a try. I did try to refill with some dot3 and sloshing around, but nothing came off, a soak with degreaser can't hurt.
I'll give simple green a try. I did try to refill with some dot3 and sloshing around, but nothing came off, a soak with degreaser can't hurt.
uHu
Bridgeburner
Have you used non-t0yota brake fluid? The OEM 5.1 fluid seems to be the best for seals/master, booster and calipers.
