Caliper Carrier (rear) - Removal & Refitting

[Neil-yaj396]

Can anyone describe in simple terms how to seperate the carrier from the piston/caliper block and replace it? I've managed to get a NOS caliper body to replace my long term sticky OSR caliper, but hadn't considered that I'd have to swap over the carrier.

Haynes is a bit simplistic/obscure and some workshop manual extract attached to an old post here suggest using a bolt to 'stretch' the carrier on re-fitting. Neither mention how to remove an refit the locating pin.

[Ferrit]

there is a little pin (look for the hole) you need to push in and then in a vice it slides off

[Ferrit]

Here you go

[SanRemo78]

There's a locking pin that needs to be depressed Neil, held in place by a spring and probably years of corrosion. Access is via a hole in the top of the iron yoke. Use a thin flat headed drift to push it down a couple of millimeters. If it doesn't move then violence is required to knock it down permanently. Did the new one come with a pin and spring?

Next step is putting it in a vice or a press to slide the caliper  out of the yoke's channels top and bottom. If it's scrap then a steel block can be used to move it with a lump hammer. If you have access to a press it will come out but keeping everything in place so it doesn't shoot out is problematic. And maybe a little dangerous if you don't know what you're doing.

If you want to get really destructive with it put it in a vice and get an angle grinder or hacksaw to work on the aluminium body. That way you might save the retaining spring and pin.

Hope that helps!

[SanRemo78]

Mark's picture obviously shows a front caliper but the rear operates on the same retention principle.

I'd be real careful about reassembly using a vice to exert pressure on the body. So careful it's a no no! Hold the yoke in the vice by all means but not under a lot of pressure. Clean the channels out carefully with a sharp blade, a chisel perhaps, to remove any corrosion, copperease the sliding faces and fit the new caliper by hand if it will slide. If you must use force then apply it as close to the channels as possible. You'll note the ally body of the caliper has high points on the channel fitting part on one side. You can press/tap on these evenly to get it in. It may be wise to make a tool to rest on both sides that you can hit with a soft faced mallet. Provided everything is clean and greased and the yoke not compressed it will go in. Try not to push it past the retaining pin without depressing that so it'll slide into place!
Guy

[Ferrit]

I have always found they need very little pressure to push it back in and you can hear the click of the pin if you have cleaned it up as described.  Yes that pin does need a wack with a punch sometimes :-)

[Nigel]

Luckily I haven't had to do this yet, however
if the pin and spring have failed or are permanently jammed
in the piston body, what to do?

Positive retention seems essential.

Would appropriate drilling and tapping, and fitting a modified stainless screw with
copaslip do the retaining job?

Modified meaning that the end of the screw would have the thread removed,
creating just a pin into a shallow 5mm hole in the piston body.

Nigel

[SanRemo78]

That's my fix Nigel, a little grub screw... Topped off with a high melt point grease.

[Ferrit]

Dog point set - Google it ;-) 

PS never had one fail as yet.  Mind you most of the ones I rebuilt was back in the early 90's :-)

[WestonE]

I have seen steel roll pins used to replace a non existent pin. But that is very hard to remove later. I like the threaded grub screw idea better if the pin is not available. 

[SanRemo78]

Learn something every day! Dog Point it is!

Roll pins can be a pain to remove if you can't punch them out the opposite side. A successful solution on an Alfa Romeo key fob to remove the blade was a little drop of superglue on a nail with a pair of pliers to pull it. Scaled up a slide hammer might work. But I think I prefer the Dog Point method, probably in stainless steel with a little thread lock. Can you tap cast iron? Maybe drill and threadsert it?

[peteracs]

I used split pin on Spider, but will use these dog point. (New to me) on the HPE ones I have in pieces ready to rebuild.

Nice to learn new thing!

Peter

[Nigel]

Dog point!
As others have said, every day is a school day.
Thanks Mark for the education. That's exactly what I
tried to say!

Nigel

[Neil-yaj396]

Thanks for all the replies guys. As suspected, way beyond my tools and abilities.....