TR2/3/3A Newbie Question regarding Girling rear brake cylinder

[Andrews]

Hello All,

I am brand new to Triumph ownership (And to be honest, car maintenance as well) and am working on the Girling rear brakes of my TR3A. I could feel that the car was having a stuck brake or brakes so I got it onto jack stands and determined that the driver's side rear wheel was locked... The rear brake cylinder piston seemed to be jammed (I even saw a little bit of corrosion in the bore along the piston head). I assumed the cylinder was the problem.

I ordered a new drum, cylinder, brake adjuster, flexible hoses and shoes and springs (I had everything apart anyway). However the pistons in the new cylinders don't move freely as I thought they would by hand... I don't want to rebuild the entire system, just to find that I haven't addressed the actual problem.

Question is how freely should the pistons move in the wheel cylinder? Or can they only be accurately tested with hydraulic pressure applied?

I appreciate the patience with my elementary questions!

 

[TRopic6]

Hi Andrews,

My experience is the pistons are pretty hard to get out by hand; I use pliers to twist & pull straight out. I guess the seal needs to be tight to ensure no leaks. The rear brakes are simple and a good place to learn the joys of home auto mechanics. They were one of the first things I rebuilt on my TR4 in 1977. Welcome!

Jeff

 

[TR3driver]

New ones can be rather stiff, especially before they get fluid in them to help lubricate the seal. They'll loosen up with a bit of wear.

Since you're a newbie, be warned that most of the diagrams in the manuals (and many web sites) show the wrong order of assembly when assembling the wheel cylinders to the backing plate. The text in the back of the factory TR2/3 workshop manual is correct, but the illustration is wrong.

 

[Andrews]

Hi Jeff,

Thanks for the reply... I won't worry too much about them then... I'll assemble the rear brake and figure that with the hydraulics hooked back up, they will operate as advertised. So far it is very enjoyable working on the little car!

Kurt

 

[Andrews]

Thanks Randall! I have found the diagrams to have great detailed photos of parts, but a little short on proper assembly... Disassembling everything has been the greatest help in determining proper assembly. I will definitely use your attached procedure for reattaching the cylinder plates (I bought a new set of those as the old ones were pretty rusty). This car is certainly teaching me patience!

Kurt

 

[SteveBones]

Hi Andrew,

Glad to hear you have jumped into the world of Triumph ownership. I wanted to let you know the folks that help, are extremely experienced and knowledgeable. I have ask quite a few questions along the way and I have been more than expressed with the help provided. Good luck and enjoy!

Steve