Guide pin rubber bushes replacement

[John Dean]

Good morning all,
Just wondering if anyone can give me some advice please. I own a2016 T6 T32 with the larger front brake callipers. I have had them refurbished and now need to fit the rubber guide pin bushes. I have replacement ORM parts and one of the bushes comes with a white hard plastic internal sleeve making it difficult to push into the calliper. Does anyone know how to get it in without damaging it? Also I’ve noticed some of the after market rubber bushes don’t have this hard plastic internal sleeve in them, is it required or could you fit just plain rubber bushes? Any advice would be greatly appreciated.
Many thanks,
John.

 

[DXX]

I noticed this when overhauling my calipers recently, the Autofren kit that I fitted did not have them and I can report that my brakes are working fine.
I couldn’t get the old OEM ATE bushes out without breaking them.
I would think that they are pressed in, something that could easily be done with a nut / bolt / washers and relevant spacer tube.
The purpose of them is unclear, odd that ATE didn’t fit the bush in both though. I can only imagine it makes the wear more even by reducing flex if one piston has more resistance than the other.
By the way, when I overhaul the calipers again I will use OEM ATE parts, much better quality than the Autofren parts that I sourced through Autodoc.
Keep us updated.

 

[John Dean]

Thank you for your advice. I will make up a system to try and press it in. I will let you know how it goes.
All the best.

 

[DXX]

A fine thread rather than a coarse thread will give you more control / feel.

 

[John Dean]

I think the problem will be pulling the outer rubber sleeve through at the same time as I think it will roll up as the plastic tube gets pulled through. Plenty of silicone grease will hopefully help!!!

 

[DXX]

I think the problem will be pulling the outer rubber sleeve through at the same time as I think it will roll up as the plastic tube gets pulled through. Plenty of silicone grease will hopefully help!!!

I use a small tyrap to compress the leading end and then cut it off when it’s in, not sure if there is enough space with the bushed version.

 

[phazer]

I've never seen an ATE caliper (on many different cars) rubber have any plastic insert. Are you sure it's not just for shipping to stop the rubber deforming?

 

[John Dean]

The old guide pin bush I took out had the hard white plastic insert in. It is meant to be in side as the rubber bush is formed around the it.

 

[DXX]

I've never seen an ATE caliper (on many different cars) rubber have any plastic insert. Are you sure it's not just for shipping to stop the rubber deforming?

Absolutely certain

 

[John Dean]

Definitely designed to be inside the rubber bush.

 

[DXX]

I’ve been overhauling calipers for 47 years, I’ve never seen a plastic bush in a guide before but I believe it’s specific to the double piston caliper (340mm brakes).
You have three choices;
Buy a refurbished caliper
Try and press the bushed guide in and see how it goes. What’s to lose?
Buy a different caliper overhaul kit.

Just very odd that this hasn’t cropped up before or maybe not with a population that renews brakes as fast as underpants.

 

[John Dean]

Guide bush pressed back in. It took some time and had to create a press with some threaded bar and washers. But it’s in without damage!!!

 

[phazer]

I’ve been overhauling calipers for 47 years, I’ve never seen a plastic bush in a guide before but I believe it’s specific to the double piston caliper (340mm brakes).
You have three choices;
Buy a refurbished caliper
Try and press the bushed guide in and see how it goes. What’s to lose?
Buy a different caliper overhaul kit.

Just very odd that this hasn’t cropped up before or maybe not with a population that renews brakes as fast as underpants.

I've just had a look and the original VW parts do have this insert on the bottom boot which is strange, as I say, I've never seen it on any other ATE calipers across loads of different cars. Seems VW/Audi use it to reduce caliper movement/vibration.

I bought the genuine ATE slider/boot kit when I fitted the 340mm brakes and they don't include the plastic.

There's nothing in the workshop manual for replacement. Looks like lots of lube on the outside and pushing them in nice and square is the way.

 

[phazer]

Guide bush pressed back in. It took some time and had to create a press with some threaded bar and washers. But it’s in without damage!!!View attachment 320894

Did you put the boot with the insert at the bottom of the caliper?

 

[John Dean]

Yes there is only one per caliper and it goes in the bottom of the caliper. I had some advice to push it in front to back which worked perfectly. If you try and push it in back to front the rubber will roll up and get caught.