Ok fellas... Here's the deal.
I have recently fitted Boxter Monoblocks on a SBug for a mate. The calipers felt and looked to be in very good order. The caliper bracket and strut kit came from VDub Engineering and are of a very high standard. The pad and rotors are brand new, as are the soft brake lines. The MC was rebuilt last year. And there is about 15mm of play at the pedal. The rear drums are new Porsche pattern stockers. The whole lot bled up fine. The pedal feels good and the car tracks and stops amazingly well, but....
The front brakes are dragging.
We have driven the car a total of 100kms since last Thursday and things don't seem to have improved. Everything is as before. Brakes done feel hot or anything after a drive, but the drag on the brakes is still there.
Any ideas?
I know its simple, but did you check the slides of the calipers. Did they slide easy?
That's my first thought.
Was there any drag after you bleed the brakes, before driving. The calipers are definitely square too the rotor, not kicked a bit causing drag.
Kev
I thought rebuilding a VW would be cheap - Shit I was wrong, just don't let the wife know !!!!
Click here for my (slowy) modded 1961 Beetle build.Hi
Got to ask silly qestions.
Is the roation of caliper going the correct way?
Is it both calpers doing it?
Can you rig up a pressure gauge in the line to check residual pressure?
Could the seals be jamming in the bores?
Steve
As above and
the caliper pistons may be sticking. Get a cailper rebuild kit - its always worth replacing seals and cleaning up/inspecting the pistons. Its always difficult to know how long the calipers have been lying around.
1961 K Ghia - Porsche 5 sp, EJ20T, Brembo's, Dble A arm susp
1974 L Bug - Porsche 944 brakes, Boxster 16's
1974 Bay Camper - EJ20, twin radiators, Boxster 16x7's
Half Beetle trailer with Boxster 16x7's
2011 Tiguan TDI 4Motion
2010 LR Discovery 4 TDV
Supposedly the calipers were fresh and off a recent wreck... The pistons moved back in sweetly when I fitted the new pads... Clean fluid came out upon compression. Didn't check for drag before bleeding, though the rotors spun free before I fitted the calipers. As I suggested earlier Steve... Both calipers are dragging equally, and yes they are on there correctly... Bleed nipples to the top.... They look to be running straight and square.
The thought that the calipers are sticking did come to mind... Thinking that the pistons might have gotten stuck on dirt ridge in the bore.
Try cracking open the bleed nipples to see if there is 1) any residual pressure and 2) the disc then spins freely.
ragged wrote:Try cracking open the bleed nipples to see if there is 1) any residual pressure and 2) the disc then spins freely.
X2 it may not be a caliper problem,possibly master cylinder.
Hi
Even if the bleed screws are at the top you can still have rotor spinning the wrong way in the calliper, there should should be a direction arrow cast onto the calliper. If it is the wrong was round you can swap the cross pipe and bleed nipple end to end.
The small piston should be the 1st one the rotor sees and the large one is the last.
Steve
The are Boxter monoblock calipers Steve... They are 4 piston deals with all equal sized pistons as far as I know.... They were marked left and right when I pulled them from the box.... But I will check that idea, and have a go at the cracking of the bleed nipples this weekend.
Rebuild kits are being hunted down as we speak.
Cheers for your replies folks.
Hi
It should have 36 & 40 mm pistons.
Steve
ps, I realised they were Boxster brakes, I just used the Willwood picture to get across what I meant by the piston position, they use odd size pistons to prevent the long pad from cocking
grumble wrote:ragged wrote:Try cracking open the bleed nipples to see if there is 1) any residual pressure and 2) the disc then spins freely.
X2 it may not be a caliper problem,possibly master cylinder.
make sure it has the correct pedal free play.
lack of free play on the MC was cause build up of pressure.
Hope that helps.
71 notchback,
Past owner of, 70 NB, 73 SB and 72 FB TLE
Try Bigg Red in the UK for rebuild kits - found them to be much cheaper than in Aus. and postage is cheap.
http://biggred.co.uk/onlinestore.php1961 K Ghia - Porsche 5 sp, EJ20T, Brembo's, Dble A arm susp
1974 L Bug - Porsche 944 brakes, Boxster 16's
1974 Bay Camper - EJ20, twin radiators, Boxster 16x7's
Half Beetle trailer with Boxster 16x7's
2011 Tiguan TDI 4Motion
2010 LR Discovery 4 TDV
