Q45 master cylinder differences, what gives!!!

[elwesso]

Ok.. I was told that the master cylinders for the 9093 were bigger than the 94s.. The 9093 had the 1 1/16 like the 300ZX.. However I found some more differences that I was not aware of. I got a master cylinder for $25 so no complaints if it doesnt work..

Heres a side by side compare of a 94 MC (left) and a 92 MC (right).. AS you can tell on the 92 MC, there are side by side ports forthe front and rear... ON the 94, there is a think that says P (assume meaning primary, aka front?) and on the end it says S (meaning secondary?)..

Also, on the 92 MC there is no bleeder valve..

Also, on the side BM-50 is stamped on the side. Incidentally, the Z32 MCs ive been trying to find also have the BM-50 stamped on the side.

[maxnix]

Are you sure that is the correct picture? Are you talking about the ABS?

Later: That's better.
Modified by maxnix at 10:50 AM 6/27/2005

[Rex]

Are you sure that is the correct picture? Are you talking about the ABS?

I gotta agree with Brian here, that looks like the wrong side of the engine bay??

NOTE: He's since changed the pic.

[elwesso]

I took the picture myself...

The ports are on the passenger (inboard side) of the cylinder...

EDIT, shame on me for being a moron!!!!!

I was going to use that picture later... But I fixed it now

[RobertsnewQ]

Z32s have two different MCs manufactured by different companies - Tokico and Nabco. It looks like th Q does (did) too. THey aren't compatible for the reasons you've noted. You have a Nabco on the left and a Tokico on the right.

BTW, the 93 Q has the 1" MC, so it's only the 90-92 with the larger one.

[elwesso]

is that good or bad?

[RobertsnewQ]

is that good or bad?

Neither. If you want to re-bend your brake lines, you can use the Tokico on your (Nabco-equipped) car. If you don't, then you will need to find a Nabco 1 1/16 MC. You can probably sell the Tokico one to a 240sx guy since they usually use that type.

EDIT:::*actually it isn't that simple *

I just remembered reading somewhere that the flare fittings are different between the two MCs - at least for the 300zx, so you will have to re-flare the lines as well as re-bend them. I'd try to find the other MC.

[elwesso]

OK, but is there any benefit for me to use the 92 one on my 94? Im not thinkin htere is......

[RobertsnewQ]

You mean other than the increase in pedal pressure and decrease in travel?

Probably not. Do you have too much pedal travel now? You could try adjusting the pushrod (the inside one to the brake pedal, NOT the booster pushrod.

I just did some more research and it turns out that the 90-93 MC is the same externally, but only the 90-92 is 1.0625. The 94-96 is a different PN.

Soooo.... If I were to do the swap I'd use the brake lines from a 90-93 with the MC from a 90-92.

[elwesso]

I have the Z32 brakes on my Q and the pedal is just way too soft... I can press it down all the way, and even when its going slow, it doesnt cause the car to violently stop like it should

[RobertsnewQ]

Hmmm - If it's THAT bad I would check for air or a misadjusted pushrod first. The MC should make a 10% or so difference.

[elwesso]

I have speed bleeders... And I bled the air probably 5-6 times.....

Maybe I'll try the pushrod adjustment.....

[RobertsnewQ]

Check for leaks too - the tiniest little weeping will cause a mushy pedal.

Does it just feel mushy all the way down, or hard but far down?

The first is likely due to a hydraulic problem, the second a mechanical one.
Modified by RobertsnewQ at 11:46 AM 6/27/2005

[redmanfx]

I have speed bleeders... And I bled the air probably 5-6 times.....

Maybe I'll try the pushrod adjustment.....

When I did my brakes I had the same problem with the pedal going to the floor. I was able to pump and get a good brake, but I had to bleed them a few time. I did it with two people even with my speed bleeders. drivers side rear, passenger side rear, drivers side front and then passenger side fornt. After that all worked great. Sounds like your getting air or have a leak. If you lived in NC we could hook you right up!!

red

[elwesso]

i mean i like the feel it just doesnt feel like its doing anything..

I looked at the pushrod, and im so sick of working under there, whatd you use to get at it..... i couldnt get anything on it...

[RobertsnewQ]

Remove the cover (3 screws)

14mm open ended wrench on the nut

needle nose pliers on the knurled section.

There's not much space in there

[911/Q45]

I was just working on my car and thought of you and your problem Wes. Did you install the front calipers with the bleeder valve at the top? If you have them switched on the wrong sides of the car, the bleeder ends up on the bottom of the caliper and it's impossible to get all the air out.

[elwesso]

I was just working on my car and thought of you and your problem Wes. Did you install the front calipers with the bleeder valve at the top? If you have them switched on the wrong sides of the car, the bleeder ends up on the bottom of the caliper and it's impossible to get all the air out.

I thought about that, and *luckily* i did put them with the bleeder on the top.. I didnt know it made any difference and I think i ended up switching the rears...

Im thinkin ill just adjust the pedal in a turn or so (I dont have morethan maybe 4-5 threads to go!) and then put some new pads, im thinkin its the pads anyway, which would line up with the advice that I was given earlier...