E30 5 lug swap brakes not bleeding properly

[Maxdtran]

Hi all I am new to this forum since I just bought a 92 e30 with an m50 swap and recently did a 5 lug swap with fronts replaced with a 97 m3 and rears were a z3 l6 hub and e36 rear calipers with 318ti carriers. everything been fine, except I can’t seem to bleed these brakes for some reason. Using dot 3 , I’ve bled this car with engine off and on from rear right, rear left, right front, left front, and slave cylinder. Well brakes are still spongy, but works. The calipers, brake pad are remanufactured and pads new. Rotors new and fronts were cut.

Am I missing something??? Never have I had this problem ever. Any advice would help.

[tomstin]

First, are you getting fluid out of the bleeders? With the swap, are the caliper bleeders at the highest point on the caliper? What method are you using to bleed (pump and hold, power bleeder, suction)?

[Maxdtran]

I’m using the pump and hold. With engine on and off. Also the calipers bleeders are low base side of the calipers.

[tomstin]

I’Also the calipers bleeders are low base side of the calipers.

Are you sure you have the calipers on the correct side? Bleeders should be the highest point on the caliper.

[Maxdtran]

Calipers flipped for bleeders to be on top. Master cylinder replaced. Still the brakes go soft after the engine turns on and I lose pressure. Only thing left that I’ve been reading is to trigger the ABS so the valve solenoid to open and bleed any air out of the system. So I read up on old threads to either jump pins 2 and 11 on the ABS unit itself or ground pins 27 and 28 on the control module itself (located underneath the cluster driver side) bad part is there’s no numbers on the ABD unit itself or the control module. The older threads do not have any clear photos. So if anyone knows how to figure out the pins. Please advise... thanks

[Jay325]

Try to gravity bleed until you get fluid.......I would imagine you still have some air in there.

[tomstin]

Two things. Have you tried to bleed the pump with the bleeder on the pump itself? Another post mentioned after you bleed the brakes go out and find some soft surfaces and force the ABS pump to activate.

[tomstin]

Two things. Have you tried to bleed the pump with the bleeder on the pump itself? Another post mentioned after you bleed the brakes go out and find some soft surfaces and force the ABS pump to activate.

[LowR3V'in]

With a new MC you need to bench bleed it very slowly and watch all the bubbles come out because there is allot with a brand new brake master.
Also are you using the 25mm because the stock MC is too small and feel very spongy then BAM it will want to lock up.

other then those two key things assuming the calipers are on the correct side it should bleed good.
maybe tap them will a small hammer while bleeding because tiny air pockets do like to stick in there.

[Maxdtran]

Thank you all. I have bench bled the Mc. Picked up a pressure bleeder. And will try it again this Sunday with the abs line 2 and 11 jumped. Ill give out an update post soon as I find out if all goes out.

[tomstin]

Did you get this figured out?

[LowR3V'in]

for future ppl.
this is how you have to bench bleed.
if you do it fast you will get the big bubbles and call it a day
but you have to, very slow, pump it.
you will see micro tiny bubbles still coming out that stick to the walls it takes some time but
they will all come out and it'll be completely bled.

Mc bleeding by jet jones, on Flickr

[Maxdtran]

Sorry for not posting an update sooner since the Coronavirus pandemic has hit Houston TX here where I live pretty hard. But no I haven’t been successful with the bleeding of the brake system and have tried every single method from a two man job, vacuum bleeder, jumped the abs, and a pressure bleeder (15lbs-25lbs).... I’m about to give up and send her to the shop..... thanks guys for all the advice...

[LowR3V'in]

so it won't even lock the brakes up?

[roguetoaster]

You clearly need to go through, open up brake line unions and figure out where there is new fluid, and where there is old. Sometimes you can have a blockage.