bad brake problem!!
- Thread starter weatherm
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
orangefj45
Supporting Vendor
more info would help.
drums all the way around or discs in front?
are any of the wheel cyliners leaking or is there a fluid leak anywhere else?
start by adjusting the rear brakes out some, should'nt take 3 pumps.
drums all the way around or discs in front?
are any of the wheel cyliners leaking or is there a fluid leak anywhere else?
start by adjusting the rear brakes out some, should'nt take 3 pumps.
brakes
X2 on the adjustment
Are the brakes still OEM all around - ALL Drums?
X2 on the adjustment
Are the brakes still OEM all around - ALL Drums?
Downey
SILVER Star
Go directly to a professional brake shop and get a "power bleed" under full pressure (this accomplishes what you can not accomplish at home in your garage) Then while this is being done a skilled mechanic can additionally check for other leaks/problems, and also check the front-to-rear proportioning. Your family will thank you for taking this precaution!!!
- Thread starter
- #7
It has goop in the rear of it and front (where you adjust them, I can see goop) but its also the wheel that has the bad axle seal that I'm replacing tomorrow so I just dont know.. plus its frozen up.
I guess I'm going to expand them closer to the drum.
I guess I'm going to expand them closer to the drum.
I can tell you from experience on my 73, the drums are a pain in the a** to get right. I replaced the whole drum system and was never happy with them. I suggest take them to someone who is familiar with 40 series drum brakes and knows what they are doing or better yet swap to 4 wheel disc like I did. By far the best upgrade I have done on the 40.
I have a 1972 40 series running 33” tall tires, and has drums on all four corners that will put you through the windshield if you are not ready for it when I apply the brakes a bit aggressively.
Where are you getting your master from? I had an issue with mine a while ago and I bought a new one from Napa. After putting in the new master it still would not bleed right. So I took it to a shop and they said it was a bad master cylinder. They then exchanged the new one for another one from Napa and that one was bad also. I ended up getting one from a Napa out of the area and this one has been fine even since. Good luck.
residual valve
make sure you have a residual valve meant for drums not discs
the pressure required for drum brakes is higher and overcomes spring pressure to keep the pistons from retracting too far into the cylinder
even with the shoes adjusted out you still have a delay to get the pistons to start pushing cause they retracted too far--hence the pumps
make sure you have a residual valve meant for drums not discs
the pressure required for drum brakes is higher and overcomes spring pressure to keep the pistons from retracting too far into the cylinder
even with the shoes adjusted out you still have a delay to get the pistons to start pushing cause they retracted too far--hence the pumps
- Joined
- Oct 25, 2008
- Threads
- 40
- Messages
- 1,331
- Location
- Central Oregon
- Website
- www.oregoncruisers.com
x2 on what kinda master you have? I went through 2 aftermarket masters before tossing an oem toyota in. My rig will stop super good now.
Same deal bleed and bleed still gotta pump...week later the masters both started leaking inside the cab.
Same deal bleed and bleed still gotta pump...week later the masters both started leaking inside the cab.
A very common misconception, and one if not corrected, will never let your drums work correctly. Follow the FACTORY method of adjusting. Tighten each adjuster until the wheel is LOCKED... then back off three clicks. Repeat for each cylinder, two on each wheel. You will never get the drums working right if you don't start with this.
If you have a bad axle seal, the drums (nee shoes) are likely soaked with grease. You'll have to discard these, clean everything up with brake cleaner, and start with new shoes. Assuming everything else is working correctly, all adjusters are free and easily moved, shoes are new or in good condition with plenty of lining, and there is no contamination of the shoe surface, and there are no fluid leaks, and your drum diameter is within spec (haven't been turned too many times), there's no way your drums can't be made to work. I've done many, many drum brake cruisers, and all have been made to work acceptably once the above parameters are met. Begin by adjusting the brakes to the factory method as I stated in my other post. Then search, study, and follow the bench bleeding method for the master cylinder first of all. Then bleed each brake, starting with the furthest from the master, and working toward the master, doing the left front last. I'd consider purchasing an inexpensive vacuum bleeder from a local auto store. You may have to repeat this a couple of times. Once you have it down to a pump or less, drive it (carefully) for a day or two. It will get better as you go. This method has always worked for me, takes some time and effort. Also, by the time you go to the time and effort for a correct and complete replacement of all the components with factory parts, you're better off with at least front discs, and can convert for about the same money.
I have a 1972 40 series running 33” tall tires, and has drums on all four corners that will put you through the windshield if you are not ready for it when I apply the brakes a bit aggressively.
X2. Mine is the same way. Better have the seat belts on when applying aggressively.
brakes
Are the Master Cylinders you are buying made for drums?
Ahem---Good reading
FAQs Proportioning Valves - MBM Disc Brakes
"What does a residual valve do?
There are two different uses for residual valves. The 10 lb valve is used to hold a residual pressure to the drum brakes
to give a higher firmer pedal. The 2 lb valve is used in the disc when
the master cylinder is lower than the calipers to prevent back siphoning of the fluid from the master. "
"What are the symptoms of a bad residual valve?
The brakes will be very spongy and you will need to pump the pedal to get good brakes." (even if they are adjusted)
Brake bleeding is a funny thing on some vehicles I had to bleed them so much I thought there was no way it could take that long---On my current 40 they felt pretty good before I even bled them
http://www.popularmechanics.com/automotive/how_to/4213448.html
http://www.automedia.com/Power-Bleeding_Brake_Systems/ccr20050501pb/1
http://www.amazon.com/Mityvac-6820-Brake-Bleeding-Kit/dp/B000FUMWTM
Are the Master Cylinders you are buying made for drums?
Ahem---Good reading
FAQs Proportioning Valves - MBM Disc Brakes
"What does a residual valve do?
There are two different uses for residual valves. The 10 lb valve is used to hold a residual pressure to the drum brakes
to give a higher firmer pedal. The 2 lb valve is used in the disc when
the master cylinder is lower than the calipers to prevent back siphoning of the fluid from the master. "
"What are the symptoms of a bad residual valve?
The brakes will be very spongy and you will need to pump the pedal to get good brakes." (even if they are adjusted)
Brake bleeding is a funny thing on some vehicles I had to bleed them so much I thought there was no way it could take that long---On my current 40 they felt pretty good before I even bled them
http://www.popularmechanics.com/automotive/how_to/4213448.html
http://www.automedia.com/Power-Bleeding_Brake_Systems/ccr20050501pb/1
http://www.amazon.com/Mityvac-6820-Brake-Bleeding-Kit/dp/B000FUMWTM
Last edited:
After installing CCOT's rear wheel cylinders on my 77, I had to pump up my brakes until I disassembled the cylinders in place and burped the air out of the top of the domed shaped seal. Factory wheel cylinders use a spring, a metal hat shaped piece with a rubber seal where as the economy CCOT's use a spring with a domed shape rubber only. I believe that's where the air was being trapped, because after a week of pressure/vacuum bleeding and adjusting, I disassemble the cylinders on the truck one at a time and this solved the spongy brake pedal. I don't know how attach a link, but there is a thread (brake problem finally solved) by my user name going over the procedure that I used.
Dave
Dave
