MG MGB and MGB GT Tech Talk
Rebuilt and just installed rear wheel cylinders in my '77 (yeah - installing those clips was loads of fun!). Then, in trying to reclaim some good brake adjusters from my '69 parts car (unsuccessfully), I noticed those wheel cylinders had locating pins, which apparently were missing from the ones I rebuilt and installed. Are they needed?
(yeah - I know - I should of just bought new cylinders in the first place....)
Thx
Bob
The bleed screw is sufficient for preventing the cylinders from rotating. The pins are different relative to the bleed screw location on several wheel cylinders that otherwise look identical but have different bores. It's a way to ensure you are installing the correctly specified cylinder.
Peter C
Basically Peter said that the GT and roadster cylinders are different and not interchangeable on the backing plates due to the difference in pin locations. There are only two different cylinders, the .800 diameter pistons for the roadster and the .875 diameter for all the GT's after the very first ones.
Davial gives you the science of the simple post of Peter....
x2 to both....all roadsters and early GTs have the smaller unit the later GTs have the larger....
I think rebuilding when it can be done is a prefered method for a DIYer...FWIW
It's more than just the 2 B cylinders. Other Lockheed cylinders for Spridgets, etc. are similarly identified.
A tip regarding installing those cylinders and that locating pin: we all, at some time, run into the issue of having to hold the cylinder in place while trying to get that clip on. On the GT I had, I removed the locating pin, tapped out the hole with a #8 tap and installed a machine screw. You then use this screw to hold the cylinder in place while you fight with the C-clip.
My memory is poor at best so I believe it was a #8 screw. If you try this, use whatever tap will thread the cylinder hole without drilling it out.
No wheel cylinders were harmed during this procedure.
Related question about the position of the locating pin on roadster v. GT wheel cylinders.
Does the GT cylinder have the pin located further down (closer to the ground) than the roadster cylinder? Reason why I ask is that I bought cylinders for a GT and the seller said he was certain the part was for a GT. When I went to install them, the pin was further down than the hole in the backplate. Did I get the wrong cylinders or is the axle in my 74GT swapped from a roadster? Thanks
