G20 Brakes

mdhoff · #1 03-15-2002, 10:03 PM

Bought a '94 G20 with 104kmiles one it. It needed new pads so i installed new ones and that is when i found the left side had more wear then the right side. When i was pushing the piston in on the right side it was very hard to push back in. The new pads seemed to darg on the right front so i put a rebuilt caliper on and bleed the new caliper but i can't seem to get any pressure to the right side caliper, in other words, the piston will not move when i push on the brakes. Thanks for any help you can give. Mark

AznVirus · #2 03-16-2002, 03:57 AM

check the brake lines, and bleed all 4 brakes in this order: rear right, front left, rear left, front right.

TIZAO · #3 03-17-2002, 10:30 PM

Does order really make a difference? If so, why?!!:alien:

:licker: :smoka: :flash:

T4 Primera · #4 03-18-2002, 06:54 AM

Primeras/G20s with ABS have 2 braking circuits arranged diagonally opposite. So you start with the farthest away from the master cylinder first then do the front one for that circuit. Then do the other circuit the same way.

Older cars had a front circuit and a rear circuit so they could just start furthest away and work to nearest.

mdhoff · #5 03-18-2002, 08:28 AM

Thanks for the reply. I found that the circuit that the right front and left rear is on was not working. I could not get much flow when bleeding. I then pulled the line from the master cyl. and tried to bleed it and all it would do is push out an amount of fluid and suck it right back in with each push of the brake. I feel that there should be a check valve in the master cyl. to prevent this. Have a rebuilt MC ordered. THanks, hope i'm going in the rite direction with this!?!?

T4 Primera · #6 03-18-2002, 01:49 PM

If it had a non return valve your brakes wouldn't be able to release.

Did you compare it with how the good circuit behaves at the master cylinder?

mdhoff · #7 03-20-2002, 07:03 AM

Well it worked! Installed rebuilt MC and blead the brakes and both circuits blead just fine. Road tested it last night and brakes work fine. In reply to the last post, i agree somewhat but if this was the case then you would never be able to bleed the brakes. Every time you opened the bleeder valve the MC would suck the last pump back. On brakes that are working rite you can bleed the fluid level down with just a few pumps. I think the MC should suck a small amount back but then reload with fluid from the MC.

T4 Primera · #8 03-21-2002, 01:52 AM

Quote:

Originally posted by mdhoff
Well it worked! Installed rebuilt MC and blead the brakes and both circuits blead just fine. Road tested it last night and brakes work fine. In reply to the last post, i agree somewhat but if this was the case then you would never be able to bleed the brakes. Every time you opened the bleeder valve the MC would suck the last pump back. On brakes that are working rite you can bleed the fluid level down with just a few pumps. I think the MC should suck a small amount back but then reload with fluid from the MC.

You are supposed to close the bleeder before lifting the brake pedal to stop that suck-back thing from happening so the master cylinder reloads from the reservoir (sp?) instead of the brake line.

mdhoff · #9 03-21-2002, 10:21 PM

Right, the old master cylinder did not reload it just sucked back from the brake line all the time. This would tell me there is some kind of a ball check or something in the MC that will suck form the brake line alittle to allow the piston at the wheel cylinder to retract some and then reloads. Mine was not doing this it only would suck form the wheel cyl. and not reload.

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