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Mk 4 Rear Caliper fitting....longer pedal travel?

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Just been to the VW parts desk to get a number of items, including a pair of caliper seals for the mk4 calipers that I am going to do the conversion with.

 

The parts guy couldn't confirm the seals the computor were indicating were correct for my calipers (even though i took them along). I think he was trying to source some mk4 calipers seals for R32, 4 motion etc which have vented disks... I told him i needed seal kit for calipers used with solid disks, he couldn't source anything. Without a number plate or VIN i couldn't give him anymore, even had the seals out to show him (Lucas items with pt no's) still no joy.

 

Does anyone know the part numbers for the seal rebuild kits for the mark 4 golf rear calipers to be used on the conversion?

 

Failing that does anyone have a mark 4 Golf that has the same spec brakes that they could PM me with an number plate to use as a reference back at the dealers to get the right part? (We did this with a trade in car, came up with seals listed amongst R32 4 motion etc even when it was a basic w reg car)

 

The price for these was about £14 each + Vat, not £8.50 + Vat i was expecting from doing a search on here....

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Just to update:

 

Looked out for rebuild kits on the net, found out Bigg Red do rebuild kits. Ordered Mk4 Golf rear rebuild kit on internet on Sunday.

 

Arrived today...seals looked smaller than those taken out. Dry fitted seals and definitely different over piston and in caliper housing. Rung Bigg Red and explained problem and what i was trying to achieve. They asked for any identifying numbers on my calipers as I didn't know the car they came off other than was expecting it to be a Mk 4 Golf. The numbers were 313\1 and 314/1. The notified me that according to their records and database I actually have Octavia/Golf estate calipers which have a 41mm bore piston and not 38mm standard golf ones! Have got to send back for exchange + £5 to cover postage and extra cost for different kit price difference.

 

Was a little worried that the calipers may not be suitable for conversion as they weren't Mk4 Golf items but was recommended, but couldn't confirm, that as long as the slider pin bolts for the carrirers were still 118 mm centres apart he couldn't see why they wouldn't fit. Measured and they are 118mm. Hopefully all will be sorted!?!

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It's exactly the same as the Corrado rear kits as they are the same piston size (38mm I think)

 

Can't imagine why he couldn't find them - easy enough!

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It's exactly the same as the Corrado rear kits as they are the same piston size (38mm I think)

 

Can't imagine why he couldn't find them - easy enough!

 

Thats what I thought. All gone out the window now I have contacted/purchased with Bigg Red and found out 38mm seal kits won't fit my calipers...I have 41mm piston bore calipers from either of the aforementioned cars. Am sending the actual seals out of the calipers back with the seal kit to cross reference the sets to make sure i get the right ones. Hopefully the calipers fit just the same as Mk4 Golf ones will.

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Long delay on following up from this....

 

Anyhow, I got the correct seal kit for my calipers, which were indeed 41mm. Calipers have been rebuilt, painted and fitted today. All works as it should with one exception.

 

Both calipers have been fully re-bled with no air coming out. However there is a longer pedal travel and maybe slightly softer pedal feel than before. Would I be correct in thinking that this is due to the piston bore being 3mm bigger than Standard mk 4 golf and Corrado calipers being 38mm?

 

There is no doubting the brake action; the car pulls up just fine when you stop (only done a stop from 25mph) and when pootling about. The handbrake holds well on flat and is a lot more difficult to drive off with it on (unlike with the old calipers, yet to try it on a slope or hill). I would say objective is achieved but no with a new problem...

 

What can anyone suggest? Larger master cylinder?.....

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sounds like you've still got air in there. I've just fitted the mk 4 rears on mine and the pedal travel/feel is exactly the same.

 

You'll need to bleed the mk4s twice as they need to be operated a few times to adjust out the piston.

the first time i did the bleed i forgot the master cylinder and the pedal travel was to the floor, i bled the rears again and the master cylinder and all was fine.

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Despite bleeding my brakes twice, I noticed after a near complete overhaul of the brake system (fitted new seals on std rear calipers, discs and pads, and a 288mm kit for the fronts with new discs and pads) that the brakes were spongy.

 

Decided to run it and bleed it after everything had bedded in, and after a matter of days, the brakes stiffened up. I really have noticed an improvement now, simply by using it and waiting to see what would happen.

 

Might work for you?

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If you get air into the ABS system it can be a right nightmare to clear it out, i'd say drive it for a little while so long as it's not dangerous then re-bleed all 4 corners and the master.

what are you using to bleed the system?

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If you get air into the ABS system it can be a right nightmare to clear it out, i'd say drive it for a little while so long as it's not dangerous then re-bleed all 4 corners and the master.

what are you using to bleed the system?

 

I'm doing it the traditional two man method. One man doing the foot pedal the other on the bleed nipples - pedal up, open nipple, pedal down, close nipple pedal up and so on. Eezi-bleed was more hassle than it was worth, just sucked air back up in...

 

My main concern isn't with the stopping of the car, its good, better than before I would say. Its just the pedal feel, where it bites is lower down the pedal travel and you have to be aware of it. Its not to spongey to be honest.

 

My only reason for bringing this thread back to life is that the standard Corrado calipers and standard mk4 calipers are 38mm. Mine are off an Octavia or mk4 Golf Estate (only found out after buying, see earlier threads). My calipers have 41mm piston bore - therefore I'm thnking it is taking more oil to move the piston, hence the longer foot travel.

 

Your experiences with leaving it a few days of normal use and re-bleeding is interesting though, I will probably do the same and wait and see.....

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humm dunno then.

 

interesting about what you say with the eezibleed as that's what i did mine with and had no issues at all.... how do you mean it was sucking air back up?

just keep the fluid in the bottle up and have no air leaks and it's the perfect basic 1 man bleed kit.

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humm dunno then.

 

interesting about what you say with the eezibleed as that's what i did mine with and had no issues at all.... how do you mean it was sucking air back up?

just keep the fluid in the bottle up and have no air leaks and it's the perfect basic 1 man bleed kit.

 

Well, you could just see the bubbles that had just been expelled from the caliper rising back up the tube toward the caliper on releasing the foot pedal. However, when you say keep the fluid up in the bottle do you mean the end of the Eezi-bleed needs to be under oil in the bottle; if so, I don't think it was so might explain my problem with the Eezi-bleed. Haven't used it for a few years and may not have been using it right this time round.

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Just been reading some historic threads on here about long brake pedals. A general theme seems to be to bleed the mk4's with the handbrake cables disconnected, pump a lot, then connect the handbrake cables and bleed again.

 

I connected the handbrake cables before bleeding. I also cranked the handbrake mechanism on each caliper by hand to push the piston out before bleeding. Will take the calipers off, wind the pistons back in, then bleed, pump, then connect the handbrake and bleed to check for air again. Hope it works.

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Your eezibleed seals might have dried out - phone Gunsons and they will send you some out - they work well but I think those kits are only designed to be used a few times, not heavy duty enough really but for the price they are great...

 

You shouldn't need to depress the pedal using Eezibleed by the way - that's the whole point of pressure bleeding so you can't damage the master cylinder.

 

I think the 41mm rears may not help tbh but I would just take it to VW if you are still having problems and get them to bleed it with the proper kit, especially if you have ABS - most dealers offer a discount for old cars so only £30 or so.

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Your eezibleed seals might have dried out - phone Gunsons and they will send you some out - they work well but I think those kits are only designed to be used a few times, not heavy duty enough really but for the price they are great...

 

i didn't bother with the seal in the eezibleed bottle as it kept leaking, as soon as i removed it it sealed up no worries.... so long as you dont overtighten the cylinder cap the kit should go fo ages.

 

You shouldn't need to depress the pedal using Eezibleed by the way - that's the whole point of pressure bleeding so you can't damage the master cylinder.

 

Although it is actually a recommedation in the eezibleed manual to pump the pedal a few times

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Just thought I would update....

 

Have just wound the pistons back into the calipers and re-bled with the handbrake cables unconnected and with the handbrake mech uncranked, one side at a time. Got some more air out on both sides. Definitley the way to go bleed then crank the pistons onto the disks.

 

Now have better/shorter pedal travel and more solid pedal feel.

 

Thanks for everyones input...

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Just thought I would update....

 

Have just wound the pistons back into the calipers and re-bled with the handbrake cables unconnected and with the handbrake mech uncranked, one side at a time. Got some more air out on both sides. Definitley the way to go bleed then crank the pistons onto the disks.

 

Now have better/shorter pedal travel and more solid pedal feel.

 

Thanks for everyones input...

 

Are you satisfied with the 41mm caliper ?

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