I just found out from a friend that there is a S4 GX model at pick your part.
I need some new rear calipers since mine don't seem to be working at all.
I was wondering if these would work on my 1990 GXL. My S5 GXL has 4 piston calipers in front and vented discs all around...

So i need a simple Yes or No if these will work..

Thanks

Oh Yes.. If infact my calipers aren't the reason as to why my rear brakes aren't working i would also like to know if the Master Cylinder off of this S4 would work on my S5 GXL.

Thanks again!

 

being an S5 GXL, i'm assuming you have rear vented discs. If teh S4 GXL also has rear vented disc, it's all interchangeable.

 

I think I can answer your caliper question, the GX(L?) does have 4 pistion calipers, and they would work and I believe all master cylinders are teh same

 

My fronts are perfect...
So bascally it comes down to..
If the S4 GX model (Canadian Base Model) are Vented rears, then they WILL swap.
If it doesn't have vented rear discs then they WON'T work...??

Is that right?

 

I doubt any base S4 model has vented rears. The US market GXL was the luxury N/A model, which did have the vented rears.

 

Can anyone confirm that SOIA is correct when he said " I believe all the brake master cylinders are the same"?
I don't want to pull one out of an S4 and then not have it work in my S5.

Also does anyone have any ideas as to why only my front brakes are working right now and not my rears?

 

Yes and no...

Many of the GXL models had ABS or AAS (suspension control) if it has either of these then they won't work on your S4 base.

In addition the brake booster is a different size, and the brake master cyl and set up is even a different shape. The S5 brake master also adds a hold down screw for the fluid tank (which is actually better as the tank is less likely to move when some lame *** mechanic braces himself on the tank.

But the S5 brake booster will work, as well as the S5 brake master (as long as the GXL did not have AAS or ABS).

So see... yes, they might work (depending on options)... but no, they are not the same.

And as far as the two rear calipers, no the GX rear calipers will not work on the GXL (or visa-versa) unless you also swap pads and brake rotors. The non vented rear rotors are considerablly thinner than the vented rear rotors.

And remember everyone, that the GX was the same as the 86-87.5 Luxury coupe/87.5-88 SE/89-90 GTU... the strippy base model with minimal brakes.

 

the pads are the same for s4 vented and solid discs in the rear

 

Well technically the rear pads are the same from 84-95, but I would not use a pad that was already cut to one rotor, on a new one without resurfacing the pad and rotor at the very least...

And once you are that far, you might as well just replace the pad as I suggested.