S15 Brake Bleeding Guide?

[dave_t]

Just finished fitting my K-Sport front set-up, and came inside to dodge the rain. thought i'd google a procedure to bleed the brakes, but nothing really definitive.

can anyone give me any info?

 

[S15_SAM]

The manual way is basically, get someone pumping your pedal slowly, whilst you open the bleed nipples and catch it in a empty bottle via some vacuum pipe plugged onto the nipple!

Make sure you keep the fluid level topped up!

Go round each caliper twice, and if the pedal still feels spongy then get the person to hold on the pressure on the pedal and then you open the nipple and get him to do 5 pumps.

Hope that helps!

 

[JaseYpk]

Get a buddy to help you do it.

There is a certain order to do them in, cant remember which, but someone will pop up and say i'm sure.
But basically, get all of your brakes plumbed in, and start with one caliper. ensure the BMC is topped up, remove the bleed valve and put a tube (a length of boost pipe works a treat) over the end of it and the other end in a bottle with your old brake fluid or other liquid in it, doesnt really matter. then with that set up, get your buddy to pump the footbrake until you have a constant stream of brake fluid coming out, no air bubbles. repeat for all 4 corners, ensuring whilst the brakes are being pumped that the BMC remains topped up as its draining out the bleed valves.

when you're sure theres no more air coming out keep your buddy to keep their foot on the brake whilst you put the bleed valve back in, thus not letting the chance for air to get sucked in.

thats how you do it, its pretty simple. just check the order in which to do each corner.

 

[dave_t]

thanks for the replies, its the sequence i wanted clarifying, and also i read you have to disable to abs pump whilst your bleeding.

from zilvia:

It's Right Rear, Left Rear, Right Front, Left Front for all Silvia's. ABS, you just pull the connectors on the ABS module to make sure the solenoid's release(or pull the batt ground).

 

[spoonman]

thanks for the replies, its the sequence i wanted clarifying, and also i read you have to disable to abs pump whilst your bleeding.

from zilvia:

It's Right Rear, Left Rear, Right Front, Left Front for all Silvia's. ABS, you just pull the connectors on the ABS module to make sure the solenoid's release(or pull the batt ground).

Close, but the BMC is on the right hand side of the engine bay as our cars are not US left hand drive, you need to bleed the longest line first, so the order for a right hand drive car is, RL - RR - FL - FR, and year disconnect your battery so open up the ABS solenoids and flush well past seeing the fluid go clean so help flush some of the old fluid from the ABS unit too

 

[spoonman]

oh year and forgot this.

If you feel that the brakes are unbalanced after install say the rears are biting way too hard before the fronts or something, get a external proportioning valve and adjust it to suit, as the factory BMC and its internal proportioning valve were designed to cope with a certain fluid volume caliper ie a BM50 in the S15 (4POT front 1POT rear) is different to a BM50 in a R34 (4POT front 2POT rear) even though they are both BM50's, and i believe K-Sport probable take twice the fluid volume as a stock caliper so the BMC might not give you a good balance, this is only a guide you may have not trouble at all and you may find yourself smacking your forehead on the steering wheel whilst smiling cause you stopped on the spot, but keep it in mind as you dont want to go locking up your rears first,

a wilwood proportioning valve so you are aware, cheap enough too
http://www.wilwood.com/MasterCylinders/MasterCylinderValves.aspx

 

[Fruitbooter]

Yeh as said above furthest away from BMC first and so on...

When I did mine the battery was disconnected but didnt realise this would do something to the ABS? Mine went okay though!

Also if the balance seems off it may be worth looking for a z32 BMC and upgrading the rears to gtst/z32 calipers and discs.

 

[dave_t]

Thanks again for the replies, all done, and have been bedding in the yellow stuff pads. will bleed them once more as the pedal feel is still slightly spongey. that being said, night and day compared to the oem brakes.

Yeah Jay, i will 100% be upgrading to the Z32 BMC and R33 GT-St rear setup in the near future before i do any track time. want to get it prep'd by the end of the year for a trip to the ring in 2013, should definitely get come!

 

[spoonman]

not sure if you have been to the ring before, but brakes and handling at the highest priority so good on ya with the k-sport calipers, are you going with a club to get full use of the track or just going on the public open day?

 

[dave_t]

It will be my long overdue first trip over there, but i'll be going with a few ring regulars. not sure if we are going with any of their various clubs, or just a public open day yet.

 

[JaseYpk]

Yeah Jay, i will 100% be upgrading to the Z32 BMC and R33 GT-St rear setup in the near future before i do any track time.

Before you make test it on a track, i'd test both BMCs (s15 and z32) to see which seems to match correctly, as because you're having a mixed brake setup the bias might change slightly..

eg - i've got R33 brakes all round, but the S15 bmc still held the correct bias front to rear. The R33 BMC i had, was making the car nose dive.

So if its not too much hassle, i'd check both BMCs before you settle for one, just so you know you've got the best option.


- i've also got the R33 BMC kicking about somewhere if you want to see if thats any use for you with your setup