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Disc caliper seals

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BobS76

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Can any one offer advice on installing the inner seals for the front disc calipers on a 1500 midget? The kit from Moss includes a set of inner fluid seals that have a diameter noticeably larger than the diameter of the groove that they fit into. Moss assures me that they are the correct part and an engineer friend who has worked with servo valves professionally and cars as a hobby assures me that the seal should have a larger diameter. Thay say that it just takes patience. Mine is starting to run out. Has anyone else experianced this before? Is there some trick that I am missing?
 
I know that in their flyer, my local supplier (Obsolete Auto) makes specific mention of this seal "appearing to be" too big. They suggest that a little brake fluid and a lot of pushing around with fingers *should* allow you to seat it correctly.

See the top of P.19, MGB example used...

https://www.obsoleteauto.com/flyers/Fall 2007_FINAL_web_16_to_24.pdf

Never done it myself... YMMV
 
Are you referring to the piston seal, or the seal that goes between the caliper halves? FYI, don't take the caliper halves apart unless you plan to replace the seal between them. As far as the piston seals, I've encountered similar issues with slave cylinders, so Tosoutherncars is correct, try lubing them with some brake fluid. DON'T get anything petroleum based near them. Be careful not to scratch the piston trying to put it on.
 
Patience and Lubing them with brake fluid.

Don't ask me how I know, but never use a faucet washer between the two halves :wink:
 
Thanks for confirming what I feared - they are supposed to be difficult. The reference in the "Obsoleteauto" .pdf makes it sound easier than this is turning out to be. I am using brake lube and am fully aware that you don't seperate the two caliper halves.
 
Dunvan,
THANKS. I had not heard of Obsoleteauto before, despite owning MG's since 1985. Good article, but even better service. The gut on the other end of the phone actually pulled an MGB kit and measured the seal diameter for me. OOPS. I have a Midget. He went and got the Midget kit and measured. My old seal met the measurement for the Midget, the new seal from Moss meets the measurement that he got from the MGB kit. Problem solved, except that I still need a new seal straight away.

Again, thanks,
Bob
 
Bob:

You can split them, just need to replace the seal.

Pat
 
BobS76 said:
Duncan,
THANKS. I had not heard of Obsoleteauto before, despite owning MG's since 1985. Good article, but even better service. (...) Problem solved, except that I still need a new seal straight away.

Again, thanks,
Bob
Click to expand...

My pleasure! Glad he was able to help.

For anyone who's interested, I would heartily recommend signing up for their newsletter. Not only is it filled with all sorts of goodies (as you can see from the online version) but the tech tips & tricks are very much centered around the types of jobs we all seem to like doing ourselves.
 
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