Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - 76 b brake poping?

hey guys i went to bleed the brakes on my 76 b and first it blew the brake slave cylinder in the passenger rear which is the brake i started with so i rebuilt it with new seals it happened again i believe i got that problem under controll now but now when you push the brakes feels like theres pressure untill you push the peddle almost to the floor and you hear and feel a pop like air rushing threw and your foot goes to the floor. when you feel that pop its also putting air into the master cylinder any ideas?

Bad slave cylinder. Unless you are all-over green, of course ... Change it, rebuilding is a false economy.
Paul Hunt 2

OTOH, are you sure you are putting the seal on the piston the right way round? The groove in the flat face of the seal should face *into* the cylinder, not out. The wrong way probably will 'pop', but that will eject fluid from the slave cylinder.

I'm not sure what you mean by "that pop its also putting air into the master cylinder". If the *master* seal is blowing then the pedal will go to the floor, but all that should happen then is that fluid will then leak from the master down the pedal. Unless the system hasn't been bled properly I can't see how anything can put air into the master. Unless you mean the level is dropping after the 'pop' and when you have released the pedal. If the pop *is* from a seal blowing then you will lose fluid as I say above, in which case the fluid level in the master *will* drop.
Paul Hunt 2

i found the problem at least one of them one of the seals in the master cylinder was shot so i ordered in a rebuild kit im ordering all my parts through moss motors is there a cheaper place or are they all pretty close in price?
Scot Hamm

I'm in agreement with Paul. Suggest you seriously consider buying yourself a new master cylinder. And - considering the labor and time involved in rebuilding, to have it fail shortly thereafter, buy new wheel cylinders, as well. It's my experience, if one blows - count on the other to go - replace in pairs. Ebay is good source for NOS (or new) parts, but others are out there (e.g.,, 20 percent off Moss).
Steve Buchina

I have rebuilt these before, and I totaly agree with the above comments - You are wasting your time with them. Buy a new one. It will be cheaper and better in the end
Frank Baker

This thread was discussed between 09/12/2006 and 12/12/2006

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.