Problem after 312mm Upgrade

[Combine 0]

Since recently fitting complete new brakes to my vr6 the brake pedal travels a long way before initially biting :( . Is this a common problem or have i missed something out?.

My upgrade consists of 312mm discs and calipers (front)

Mk 4 rear calipers and discs, braided hoses all round and dot 5.1 fluid.

The system has been checked for air and is fine.

 

Any suggestions please?

[mrbeige 0]

Did you pressure bleed the system?

[dinkus 10]

What brake pads did you use on the rear? Apparently if you use the Corrado ones the brake pedal does tend to travel further than if you use the late Mk3 GTI pads which are a bit thicker.

 

It doesn't make sense, but it's true :lol:

[Baz2004 0]

having the exact problem myself for ages with 2 pots and mrk iv rears been up the wall thought about replacing the MC recently !

[Kevin Bacon 5]

Yeah it's a funny one this.....

 

I'm convinced a lot of it is down to the rear brakes. When freshly fitted with new pads and setup right...the pedal is solid. But as the pads wear in and therefore more travel in the calipers, there goes your pedal again :roll:

 

I use MK4 pads which are the thickest of the three types available (MK2, late MK3 and MK4 - 1mm thicker than eachother) and the pedal is rock for about 1000 miles and then gradually increases in travel again.....but it's fine at the moment and according to Vince at stealth, is the best pedal he's ever tried on a VR.

 

I need to look into some alternative arrangements at the back and I've already worked out how to use Focus rear stub axles as a way of dumping the sheeeite taper bearings..... just need to look for some small 2 pot alloy calipers to fit to them without being too big in piston area as to overwhelm the MC and cause a long pedal again....

[Combine 0]

Not sure which pads are on the rear as a friend of mine did all the work, he runs his own vw garage in middlesbrough. Will ask him today but looking at the replies seems like its the mk2 pads that are fitted>

[sciroccotune 0]

since the pads get thinner quick, can you not use a vented rear disc, they have to be 2x as thick. im sure i have seen 5 stud passats, 1.8t, with these???

[24V Renshaw 0]

Have you tried adjusting the preload on the servo/pedal connection?

 

Jay

[Kevin Bacon 5]

I thought that just raised or lowered the pedal?

[Madjackal 0]

Would not a smaller master cylinder counteract this problem?

[24V Renshaw 0]

I thought that just raised or lowered the pedal?

 

As I understand it, the pedal will always stay in the same position as it hits the stop and the brake light switch.

 

Jay

[Kevin Bacon 5]

Hmmmm.... I might have a play with the adjuster this weekend then.

[Kevin Bacon 5]

Didn't make any difference unfortunately....

 

I had to redo the bearings at the rear though as the cheap ones I put in from GSF wore out after 3 weeks! I put in some dealer MK4 pads which are superior to anything else and the thickest available of all the solid rotor'd rear cars, chamfered edges, sticky backed for squeal reduction etc etc...

 

Pedal is rock solid. It's taken all the slack out. I used to sand 0.5mm off the MK4 pads as they're a bit thick when used with the rado 10mm discs (MK4 discs are 9mm) but didn't on this occasion as I discovered the MK4 calipers can be wound right in to give plenty of clearance without crimping the piston seal on the pad.

 

Defo recommend MK4 rear callies with MK4 pads from the dealer. Sorts the pedal right out.

[dinkus 10]

Ooh - good to know Kev :)

[kebabman 0]

Is this problem evident with 288mm brakes as well?

 

I'm about to fit a set, any other tips? Don't want to end up with worse brakes than I have now! :?

[Kevin Bacon 5]

288s won't be worse in terms of outright braking power, they're miles better, but the 288s/312s don't sort the long pedal. You need the MK4 calipers and pads to sort that.

 

I'm a press the pedal harder kind of driver instead of relying on over assistance, but at slow speeds the pedal can be a bit mushy on the VR....but with the 288/312s, stand on them at high speeds and they're excellent.

[kebabman 0]

Oh I'm fine with the long initial travel, infact I prefer it! Borrowed my mates VTS for Oulton on friday and the weak but instant bite was pissing me right off! Was just worried it would be even longer than it is now. Cheers. :)

[Kevin Bacon 5]

Nah it won't be longer ;-)

 

Know what you mean about modern brakes. I borrowed my mate's MK4 once and the first time I tapped the brakes I thought I'd stalled the engine or driven into something......waaaaay over servoed! The VR brakes are great for scrubbing off 10mph gently. Try it in the MK4 and you go through the screen.....hard to drive smoothly.....and the irony is they fade like feck at 100mph where as the 288/312s just stop you :-)

[kebabman 0]

Cheers for the reassurance Kev. :)

 

Let me just check, 288s are a straight swap with the standard brakes, nothing more required than discs, calipers, carriers and pads?

[Kevin Bacon 5]

You also need the MK4 hoses (MK2 to Banjo), otherwise, yep, straight swap ;-)

[kebabman 0]

Ahh got them too, cheers! I'll stop hijacking peoples threads now. ;)

[Baz2004 0]

Do you have a part no on those pads kev?

[Combine 0]

Cheers Kev, gonna get some mk4 pads asap