New TC Rear Wheel Cylinder Faulty

[Nigel D]

Just replaced the rear brake shoes & one wheel cylinder on my TC, bled the brakes & took it out for a test run. On regular / gentle braking at end of my road all worked fine, brake pedal only travelling an inch or so ably stopping the car.

Drove onto a main road & again on regular braking all was fine. Waited for a gap in the traffic to test emergency stopping power, stamped on the brake pedal and ........ nothing, pedal went straight to the floor! Coasted to a slower speed, foot off brake pedal and gently back on the brakes worked ok again & pedal only had around an inch of travel again.

Limped home & found hydraulic fluid leaking by wheel with new wheel cylinder, removed drum & saw the new shoes were covered in brake fluid. I clamped the wheel cylinder pistons together and had my long suffering assistant (aka my wife) gently push the brake pedal, all ok. However when she pushed very hard on pedal the cylinder turned into a fountain - but not from the piston ends.

Confused I removed & dismantled the cylinder & upon very close inspection found a hairline crack the length of the bore (see photo attached). I believe the crack stayed effectively closed together on light braking, but on heavy braking it opened up & result was a fountain!

Never heard of this before, anyone else ever come across similar? BTW the new wheel cylinder was the same one available via multiple suppliers (at least here in UK), with R272 moulded on side.

As is often found, MG T's still have the power to surprise!

Nigel

[Steve Simmons]

Wow! That's a new one on me.

[Gene Gillam]

Agree...never, ever saw that before. D A N G E R O U S !

[Rick Waters]

Had a similar experience many years ago. When I bought my TC, all four brakes were a soggy mess, in fact, I'm not sure why the car even stopped. At that time, I decided to have the original wheel cylinders sleeved with stainless, and took them to be done.

When I went to pick them up, the machinist pointed out that both the front wheel cylinders were cracked, and that it was not wise to use them, sleeved or otherwise. I actually had new stainless cylinders made, but subsequently found NOS cylinders, and that's what's on the car now.

But, I am surprised to see that new cylinders would come with cracks since there is no dificult technology inherent here.