Princess Calipers
Princess Calipers
Author
Discussion

johntom

Original Poster:

248 posts

233 months

Sunday 10th March 2013
quotequote all
Hi
i am just about to start rebuilding/refinishing the 4 pot calipers i bought off the bay last year and wondered about the brake lines. Do i use a link pipe as pictured or do i go for a 'T' piece and which caliper holes do i use for the inlet(s)?



My plan is to use the existing drilled single discs i bought last year (which have only done about 200 miles) and remove the spacers from the 4 pot calipers when i rebuild, then just buy new greenstuff pads? Otherwise i will have to replace the discs again, any thoughts on the benefits of single and vented etc?


Edited by johntom on Sunday 10th March 20:36

Wedg1e

27,040 posts

295 months

Sunday 10th March 2013
quotequote all
Strikes me as a bit pointless to go to all that trouble and then not fit vented discs.

The inlet is where you have that bolt threaded in.

johntom

Original Poster:

248 posts

233 months

Monday 11th March 2013
quotequote all
Hi
Will the brakes be more effective with the 4 pots than the standard 2 pots (using the standard discs), if so how is it pointless?
I just didn't want to waste perfectly good drilled/grooved discs if the improvement to vented is minimal, but if its worthwhile then I will change the discs again - hence the original question.

Which is the prefered brake pipe set up (link pipe or 'T' piece) and if I use a 'T' set up, presumably there will be 2 inlets per caliper ?
also will I need 10mm spacers (i will measured what's already fitted)?
Thanks


Edited by johntom on Monday 11th March 08:18

al 350i

974 posts

225 months

Monday 11th March 2013
quotequote all
hi john, its worth doing the maths on how much its going to cost before you start, the rebuild kits are not cheap and very hard to find. you might be better off sending them to someone like http://biggred.co.uk/ you'd have to check but i think they charge around £160 per pair.
But the princess calipier really isn't all that good and by the time you've bought new disc's (if you can find them!!!) you might as well go for wilwood,AP or similar upgrade, if i was to do mine again i think i would have gone down this road.
best bet is to get people thoughts on here what is the best solution or up grade.

Jack Valiant

1,894 posts

266 months

Monday 11th March 2013
quotequote all
Hi John

Well i did the 4 pot Princess upgrade recently pre the engine upgrade. I used stainless hoses and a 'T' piece to feed both sides of the calliper. After a bit of a phaff about to bleed them properly they work very well. The key plus for me was the slightly firmer brake "feel" and of course the weight of the actual calipers. In terms of performance comparison, there is not a lot in it compared to a well set-up ex Granada and vented disc to the Princess system in my opinion. Both options were from a car that probably weighed double the Wedge anyway. The key issues are the size / calibre of the master cylinder and the condition / performance of the servo / pads / fluid.

Chris

al 350i

974 posts

225 months

Monday 11th March 2013
quotequote all
you'll be putting them new brakes to the test now chris!! biggrin

Jack Valiant

1,894 posts

266 months

Monday 11th March 2013
quotequote all
Hi Alex .... Not yet as i am running in the engine, but I will be!! Crap weather though... hows that Merc going?

al 350i

974 posts

225 months

Monday 11th March 2013
quotequote all
Merc will be next saturdays job if the weather is better!!!

Wedg1e

27,040 posts

295 months

Monday 11th March 2013
quotequote all
johntom said:
Hi
Will the brakes be more effective with the 4 pots than the standard 2 pots (using the standard discs), if so how is it pointless?
I just didn't want to waste perfectly good drilled/grooved discs if the improvement to vented is minimal, but if its worthwhile then I will change the discs again - hence the original question.
TVR evidently thought it was worth going to the vented setup that Ford had thought it necessary to fit to the Granada. Some people report only minimal improvement using the 4-piston AP over the Ford (Girling 2-piston) caliper, others say they're the best thing since sliced bread.
It probably depends on several other factors such as how you drive, what pads you use etc.. Personally I'm not that impressed with the Girling/ vented setup on my 390, I still have to fit my AP 4-pistons but am mindful that some people see it as almost a pointless change; hence those who go for the serious conversions that are sometimes seen on here.
Let's just say I'm glad I don't have the standard 280/350 setup wink

johntom

Original Poster:

248 posts

233 months

Monday 11th March 2013
quotequote all
Hi
Thanks for the replies
I bought the rebuild kit shortly after the calipers so all that's in hand, I have rebuilt other Tvr and Porsche calipers so no worries there either.

I just started to wonder if there was much to be gained from going to vented discs other than cooling and would the 'drilled' discs I have already fitted compensate for this cooling?
Surely the braking effect would be the same regardless of single or vented ?

Also if i use a 'T' piece which holes do the 2 inlets use as the link pipe method uses 1 inlet and 2 holes (will there be a hole that needs blocking or another bleed valve?
Many thanks everyone

Wedg1e

27,040 posts

295 months

Monday 11th March 2013
quotequote all
johntom said:
Hi

Surely the braking effect would be the same regardless of single or vented ?
Pretty much, right up to the point where the brakes start cooking wink That's why I mentioned driving style... if you drive like a woofta it may never be problem; if you do trackdays you won't make it round the first lap biggrin

johntom

Original Poster:

248 posts

233 months

Tuesday 12th March 2013
quotequote all
Ok i am going to change to vented discs, i have a supplier that has the correct vented discs (74mm high) and can supply them in grooved and/or dimpled/drilled etc at £80/pair.

can anyone confirm the required spacer thickness (Princess 4 pots/Granada discs) as some old posts suggest 10mm while others 15mm and if larger than 10mm, where would i get them ?

al 350i

974 posts

225 months

Tuesday 12th March 2013
quotequote all
could not advise on 10mm or 15mm but you could try here for kits

http://www.ebay.co.uk/itm/PRINCESS-4-POT-BRAKE-CAL...

|http://thumbsnap.com/CdBGHsNF[/url]

johntom

Original Poster:

248 posts

233 months

Wednesday 13th March 2013
quotequote all
hi
thanks for that, but i think they only do 8mm and 10mm.Supsect i need wider than 10mm if anyone can confirm ?

al 350i

974 posts

225 months

Wednesday 13th March 2013
quotequote all
will probably have my wheels off at some point over the weekend, if i do i'll try and measure the spacers.

wooly350i

2,248 posts

238 months

Wednesday 13th March 2013
quotequote all
I would have measured the ones ive got off the car but they are up in the roof of the garage and i cant reach em yet coz i cant move the car,may get a chance at weekend if not too late for you. One step forwards and two steps back in my neck of the woods at present,john

johntom

Original Poster:

248 posts

233 months

Wednesday 13th March 2013
quotequote all
Hi
Yes over the weekend would be fine. I have ordered new 'grooved' vented discs and started to dismantle the calipers in readiness for having them blasted and powder coated, but nothing goes smoothly, I connected the calipers to the air line and as you would expect 1 piston from each caliper is seized !
In desperation I have removed the top piece of the old seals and left them soaking in plus gas, will try again tomorrow with some heat.

johntom

Original Poster:

248 posts

233 months

Saturday 16th March 2013
quotequote all
Finally got the 2 seized pistons out. In the end I split the calipers, cut a bolt down so it just fit across the inside diameter of the piston, then fitted it with a nut on the thread. When it was in the piston I loosened the nut so it increased the length of the bolt just enough to grip the inside of piston. Then I was able grip the bolt with pliers and twist the piston free with the help of a soaking of plusgas.

johntom

Original Poster:

248 posts

233 months

Monday 18th March 2013
quotequote all
The new discs have arrived today and the princess calipers have been dropped off for powder coating.

Edited by johntom on Monday 18th March 20:58

al 350i

974 posts

225 months

Wednesday 20th March 2013
quotequote all
sorry it took a while but finally got out to car today!

i've now seen your disc's are a little different to mine, i have a separate alloy bell and then disc rotor is mounted to this with allen bolts.

disc is 285mm dia and 27.5mm (although were probably 28mm originally but had to get them machined as had sat around 10 years). I have 2 spacers between the calipier each are 7.5mm = 15mm spacer