Split Triumph Calipers?

[Robert in Cumbria]

The Triumph front brake calipers from my Hybrid Roadster rolling chassis need overhauling, the piston bellows dirt shield is cracked and perished and the pistons are inhibited by some corrosion at the top of the bore above the rubber cylinder seal. In order to clean the bore tops more effectively I would like to split the caliper.

I have always been aware that spliting calipers is a big no-no. What are the members feelings on this?

I plan to install a full set of new seals but there will not be a new 'O' ring for the port between the halves of the caliper in the kit. I guess if it needs replacing I could use a generic 'O' ring from a selection box?

The caliper is marked 12SP and the pistons are 42.75mm Dia.

[stevejgreen]

Re: Split Triumph Calipers?

I think it's a rumour, I have split many a caliper, with no problems.
Looking at those who have modified Princess calipers, adding a spacer block between the two halves to accomodate thicker disks, it is not particularly unusual.
I have used selection box and 'proper' O rings (cant see the difference apart from budget ones) to replace the internal O ring.

So far, none of my calipers have leaked or failed in any way.

My only reccomendation is to keep wire wool as far away from a caliper as possible, the harshest cleaning medium I use is a Nylon pan scourer.

[gary.price]

Re: Split Triumph Calipers?

Abit different but i used to split the calipers on my land rover as they were sezied solid to the axle. The land rover forums say its a big no no. I didnt have any problems. i reused the o rings. i wouldnt reccomend just using any o ring. They will rot over time and leak. I would probaly risk it on something not as important than the break. Try and remove the pistons abit before taking the calipers off. Tho mine were so bad i had to buy 2 new calipers. Do they do stainless pistons for these? i would get them.

[Robert in Cumbria]

Re: Split Triumph Calipers?

I have split them in the past with no consequences but have become (a little) more cautious since those (silly) days.

I was just wondering what the current concensus of opinion was nowadays.

I have removed the pistons from one caliper and the other the other caliper pistons are free I just can't pull them out without risking damaging the dust seal groove. I have tried air and tapping the calipers hard with a copper mallet, my next move will be a grease gun, that WILL push them out.

The only reason I am considering splitting the calipers is because the top rim of the bore is corroded and the expanded rust is preventing the pistons moving freely. I can clean the rust off without splitteng the calipers but it will be MUCH harder to get them properly clean. I guess I am just being lazy!

The pistons are in pretty good condition all considered.