MGB 1977 MGB Brake issues

[Celtic 77]

Just recently picked up a 77 B (Number 6 over the years), looks very good, numerous new stuff, and a factory hardtop! Only problem is the brakes... Allegedly has new brakes, pads, drums. But very exciting to drive on the northern NJ highways getting it home. Probably has about 25% stopping power. Emergency brake is good. New Master cylinder. Thoughts? We're bringing it to a local Brit car guru on Monday. Lastly, is a brake booster really necessary? As I recall, effort was never an issue.

 

[JPSmit]

welcome - sounds like a great project. (assuming you don't die )

Assuming you have a hard pedal, two thoughts.

1. How are the hoses? were they replaced? ordinarily a perished hose stop fluid flowing back so is more likely to have the brakes seize than not work, but, still worth checking.

2. Were the rear brakes adjusted properly? With new pads etc it is likely they didn't bother. You should be able to jack up the rear wheel, tighten the brums until they grab and then let them off till the wheel spins. On clue could be how far back you have to pull the emergency brake to make it work - too much and the rears for sure need to be adjusted.

good luck!

 

[Joe Reed]

Could easily be a faulty booster.....or the hose from the intake to the booster...

 

[kilofoxtrotalpha]

A servo isn't generally considered essential because the original braking system was over-engineered (like much of the rest of the MGB) and is much more than adequate. But a servo makes braking feel more like that in a modern car. Although it feels easier, it won't stop you any quicker. We fitted one to our 72 Roadster, and can recommend it. If you have 25% braking power, it's probably a fault in the hydraulics.

 

[Celtic 77]

Thanks for the input.
Well, found the beginning of the issues...leaking rear wheel cylinder. Brakes definitely a necessity her in northern NJ. Future project includes dumping the CAT and eventually a "real" exhaust. Shame on us for not taking it for a test drive. But, after 5 previous MG's, who would've thought! Overall, though, the car looks good. Two small rust spots at bottom of front fenders. Patch panels next! The car came with a factory hardtop, new top, and solid floors with excellent interior.

 

[Celtic 77]

FYI... Update on brakes. rear wheel cylinders replaced, rubber brake lines to caliper replaced. Steel lines cleaned out and guess what came out. Compacted 4" worm of rubber that apparently built up and compressed the bits of rubber until barely stopped the car. Next issue is excessively fast idle that started right after a 50 mile drive. CD 175 carb...Thoughts anyone?

 

[DrEntropy]

Which choke mechanism? I'd look to that first. Then the air bypass valve.

 

[JPSmit]

Before you start too much diagnosis, it took me an embarrasingly long time to realize that you need to set the idle with the engine hot. You might just want to adjust it and see what happens. If it is stuck however, check if the cable is binding before you go too far into the carb.

 

[DrEntropy]

Disconnect the cable from the carb and see if the thing drops to some reasonable RPM.