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MG MGB GT V8 Factory Originals Technical - Brake pedal Travel
I have a lot of travel on my brake pedal and have to push quite hard at the bottom to make them work, I have a standard MGB master cylinder fitted as the V8 one would not fit. The brakes stuck on a few days ago and then released the next day.
I have replaced the rear drum brake cylinders and they have not stuck on since, I have V8 calipers one the front and bigger discs, all the brake system is new.
Can the master cylinder rod be adjusted? or shimmed out,or is there some sort of pressure reducer available? or is there another way to get the travel back?
Thanks in advance.
‘Regarding the brakes being stuck on’
I recently had a problem with the front disk brake not releasing and perhaps the information might help you.
As I pulled over to the side of the highway to consult a map I noticed the brakes felt a little stiffer than usual. As I tired to pull forward to rejoin the traffic my front brake was so tight I couldn't move the car.
This car is meticulously maintained and only 2 weeks before this episode the brakes had been removed and inspected.
I backed off the bleeder valve and the car moved normally. I found a big pull out as soon as possible and ran the car up and done the empty pull out applying/spiking the brakes trying to duplicate the problem. No luck. 2 weeks later the brakes are still fine.
The only thing I can think happened is a small pebble got stuck between the piston and the caliper which would not allow the piston to retract. Once the pressure was released the pebble fell out and the brake action returned to normal.
Another time I had a problem with a brake piston not releasing (different car), the cause that time was a slightly flatten brake line behind a brake line clamp which had been tightened to much. The brake pedal being activated was able to force the fluid through the line but once the peddle was released the brake line was crimped just enough not to allow the fluid back.
There is no adjustment for the master cylinder rod as far as I can see.
Are you confident that the system is properly bleed?
Hope it helps
The system is properly bleed, i did it again today just to make sure, i have recently replaced all the brake pipes, but will check that there is not a flat pipe anywhere, when the brakes stuck on i was able to drive the car home(about 3 miles)although i had to change upto second a bit quick.
I don,t think it will stick on again, its the travel which i need to sort out.
|Have you checked the rear brake adjustment? If it is set to loose, the wheel cylinders will take more fluid to move the rear shoes, meaning more pedal travel.|
I have just replaced and adjusted the rear wheel cylinders, i adjusted them until it locked the wheel and then back them off 1/2 turn so i don't think this is a problem.
I have managed to get my brake pedal travel back by adjusting the master cylinder rod, it doesn't seem to have caused any problems.
I have checked it on a rolling road and driven it around for a while, so hopefully that is it.
Nice to have some confidence in the braking.
Thanks for posting the end result.
I am curious though how you adjusted the master cylinder rod?
I undid the 2 nuts holding the master cyliner on, moved it away and got someone to put their foot on the pedal a bit to bring the 7mm lock nut into an area where i could unlock it and then undid the locknut and turned the rod to extend the length and relocked the nut.
I only extended it by about 2mm but that made a lot of difference to the pedal travel, you have to be careful to not go to far as it will lock the brakes on.Try the car for a couple of miles and make sure the car is free to run.
I am not saying this should be done!!! as i have seen nothing in writing that you can do this, but it has solved my brake pedal travel. I did have it properly checked on a rolling road brake tester afterwards though.
This thread was discussed between 23/09/2006 and 01/10/2006
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