Brake Upbrade

[stagasaurus]

Ok, just trying to get my head around this as there is mixed chatter.

I have a Series 1 C34 RS4 (Automatic, of course)

I have purchased R33 GTS-T Callipers, hard brake lines, rotors and pads.

from my understanding I will also need brake lines (from what I have read, R32 GTR brake lines will fit..

1. Do I need the lines all round, or just for the front callipers?

2. Do I need to machine down the OD of the rotors. (I have access to a brake lathe, so that's fine.)

3. Should I be spacing the callipers off the mounting plate at all? (Or are the r33 rotors matched offset for running the callipers with my hubs)

any other things I have to worry about?

Thanks.

[RS4-S]

1-if your going to the trouble of doing front lines you might aswell buy a braided brake line kit and do the lot while your there. if you have the hardline then yes R32 and R33 GTR brakeline kits will be fine. the 2 are the same part number line kit with most aftermarket manufacturers

2-no

3-no (correct)

[stagasaurus]

Thanks for the help, and yes i'm going to replace all the lines with new braided lines.

Just thinking about buying some slotted rotors instead of the nissan ones, and some different/higher heat ranged pads. Trying to decide how the car will end up..

Also, what was the talk of locators/retainers?

Edited May 17, 2011 by stagasaurus

[RS4-S]

the series 2 (and apparently some series 1's) have a 14mm hole in the hub, so using R33 GTST calipers they use12mm bolt, so people were making little sleeves outta pipe and whatever else to take up the slack and locate the caliper properly

[stagasaurus]

Oh ok thanks, ill just cross that bridge if i come to it.

Thanks for all of your help.

[whitenight27]

Ok I have something for u. I went and did this with 32 gtr brakes. Removed the bit in the caliper drilled and taped to the s1 14mm bolt. Got it all fitted up bleed it and no pedal. Had a swoosh sound when the pedal was pressed. It would get some pressure when u pumped it a few times and the car would stop. But as soon as u let it off nothing again. Went to a shop they bleed 1L though the system with no change. Then got the master and booster cheaked out all working fine. After the front lines where clamped off there was a nice pedal. So I replacing all the stock bits so I have a car again. My question is do u think the calipers need a rebuild or bigger lines?

Edited February 5, 2014 by whitenight27

[Ben C34]

Rebuild. What would bigger lines achieve?

[whitenight27]

Yer thats what I was thinking. Perth brake parts was trying to tell me I needed bigger lines. I told them other guys have done this using stock lines with no problems. Just hoping with all the stock bits back on its all good again.then will do a rebuild on them

[Ben C34]

Did they mean longer? bigger diameter makes no sense or difference.

[whitenight27]

Nar I think they mean larger diameter. Thinking they just trying to make a sale. Is there any thing in side the caliper that would hold pressure on to the line.

[Daleo]

They definitely sound like they're trying to make a sale.

Split the calipers & check the internals out; it's not hard to do, and if the seals are ok, you can just reuse them. The sandwich O-ring can't be bought new anyway.
Just mark each piston & seal & put them back where they came from.

[3Katz]

Did they beed it with a vacuum bleeder or with the pump and release method? The reason I ask is because I recently did a brake upgrade and couldn't get a good result with the vacuum bleeder. I had to bleed it up manually to get every last bit of air out even though it looked ok during the vac bleed. Being a brake shop surely they would know what they're doing but may be worth a shot, especially seeing as they recommended "bigger" lines...

[whitenight27]

The shop that did it was a mechanical work shop they just asked the brake place some info.they tryed both methods with no results

[whitenight27]

The thing is it had no pedal at all unless u pumped it at least 2 to 3 times. Then about 50sec later it eould have nothing again. Thats while the car was running. When off it just feels very spongy

Edited February 5, 2014 by whitenight27

[KiwiRS4T]

Not sure what "bigger" lines are supposed to achieve. I have 8 pot D2s on the front and haven't changed my lines (except for braided lines to the calipers).

[3Katz]

If you've clamped the lines just before the calipers and the pedal feels fine then that eliminates the master cylinder bypassing internally so the problem must be in the calipers. I can see possibly one of three things happening - 1 There is still air trapped in one or both of the calipers. (I would suggest the ABS unit might need bleeding but clamping off the calipers seems to have eliminated that) 2 There is a leaking piston or sandwich seal (in which case you should see fluid leaking externally or 3 For some reason the pistons are being pushed back into the caliper too far when the pedal is released. This can happen with excessive disk run out or a warped disk but only if the wheels are turning and it sounds like it's playing up even before you get to go for a drive. When the pedal is released the seals will 'return' the piston back into the caliper slightly but should be nothing like you are experiencing here especially with stock stuff. Strange.....

[whitenight27]

The rotors are y slot rotors. There is no leaking out side of the calipers its just weird

[whitenight27]

Ok car is all fixed using the stock calipers. I split one caliper to have a quick look. The 2 little o rings look like new and the seals around the pistons look good as well. How hard is it to remove the pistions? And whats the easiest way

[3Katz]

The easiest way I reckon is to push them out with compressed air, it may be a bit harder to do now that they're split but if they were together I'd put a block of timber in the middle of the caliper (where the disk would usually run), close the bleed nipple and carefully using an air gun put compressed air into the caliper through the hole where the fluid would usually enter. They can come out with a fair bit of force hence the timber so go easy and make sure your fingers aren't in the way... If the seals were the problem in this case with no pedal I would expect to see fluid leaking from the caliper when they were fitted up and tested. I'm not familiar with these calipers but being stock in a stock position I would expect them to be very easy to bleed. If you do give it another go and run into the same trouble a technique I sometimes use (mainly on bikes because some can be a real PITA) is to leave the caliper unbolted, do the old piece of timber between the disk pads ensuring it's at least as thick as the disk so the pistons can't pop out and hold the caliper in a position so the bleed nipple is at the very top and bleed like that. Air can be a real bitch to get out depending on the set up. That's if air is the problem, sounds like it to me but as you say it's been bled and bled. Make sure you post up what the problem was once you've solved it!

[whitenight27]

Will give that ago. Yer will do. How think Should a 32 after market rotor be? I ask as was told if its not the right size might cause problems with the pistons working right