Hi all, I am refurbing a pair of R65 ATEs, thoroughly cleaned them and put in new (aftermarket) seals and SS pistons. While the pistons go in smoothy on both inner halves, the pistons will not go into the outer halves. I think the piston crown does manage to go into the seal, but it will not go any further as if the seal is binding on the piston. The seal recesses look ok, nothing to prevent them from seating. I've tried silicon grease and brake fluid, neither does the trick. C-clamp no joy. Anyone had such a problem with a caliper rebuild to get a piston in?
R65 ATE rebuild problem
- Thread starter Dr. Evil
- Start date
Junk them they were crap from the start for some unknown reason
and replace with Brembo of the same era, They were a MUCH better caliper and easier and cheaper to find 
I had this question from folks Loads of times
Or get local machine shop to Finely polish a thou or 2 more off the pistons
Thanks so much. I may have come across one of your posts somewhere. Indeed I just bought a pair of new Brembo P2F08s 38mm 108mm which are quite inexpensive off Omniaracing.net and they went straight on, though I haven't tested them yet.
In hindsight, I would definitely not have bothered with refurbing the ATEs, but now that I have done most of the work and bought new pistons and seals, I was thinking I may as well put them back together rather than trash the lot. I will try to polish the pistons down and see if that does the trick. Maybe the original machining of seal grooves of those ATEs is not 100% consistent between the two sides of the caliper.
In hindsight, I would definitely not have bothered with refurbing the ATEs, but now that I have done most of the work and bought new pistons and seals, I was thinking I may as well put them back together rather than trash the lot. I will try to polish the pistons down and see if that does the trick. Maybe the original machining of seal grooves of those ATEs is not 100% consistent between the two sides of the caliper.
before you do anything ...MEASURE . the seals old against new . then pistons and holes . i'd try all the pistons in all the holes. also old pistons against new ones.
did you get you parts from https://powerhouse.uk/ ? if they are incorrect give them a call , i've had stuff from them , always helpful , if you talk to Mr Blackadder ( i kid you not ) i'm sure he will be able to help . just don't start modifying something , cos you won't be able to send it back if it's wrong.
they do a refurb service too.
Thanks for the tip about powerhouse. Unfortunately I don't have the old seals, but the new seals are identical (sourced from reliable suppliers), as are the new pistons. I didn't measure the differences between the two sides of the calipers. Time is short so this is going to sit on the shelf for now.
Meanwhile, new Brembo calipers supplied by https://Omniaracing.net are now on, new 16mm M/C fitted and new brake hoses made up by https://www.speedingparts.eu so it is slowly coming back together.
For the record, the OE brake hoses are 50cm long end-to-end, with M10/1mm male convex on one end, M10/1mm concave on the other. The short one from the M/C to the y-adapter is 15mm, same connectors. I had bought the r65 hose set from Siebenrock, but wasn't impressed with the ends on they put on them.
Meanwhile, new Brembo calipers supplied by https://Omniaracing.net are now on, new 16mm M/C fitted and new brake hoses made up by https://www.speedingparts.eu so it is slowly coming back together.
For the record, the OE brake hoses are 50cm long end-to-end, with M10/1mm male convex on one end, M10/1mm concave on the other. The short one from the M/C to the y-adapter is 15mm, same connectors. I had bought the r65 hose set from Siebenrock, but wasn't impressed with the ends on they put on them.
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