PC2

I just received a set of used '92+ rear brake calipers and I need to verify that they are what they are since there's no Porsche part numbers on it. The only numbers I can find are 20.4692.00 with a circled 92 and 20.4691.00 with a circled 89. I'm assuming that one was made in '92 and the other in '89 for C4. What I also noticed is that the "Porsche" name is casted on the 89 and painted on the 92. Can someone help me please.

pete000

Just curious where you got them and if they were suposed to be a matching set? I am concidering doing an update on my 91 I have seent them for 200 bucks on ebay.

Bill Gregory

Maybe food for thought: when buying used calipers, rebuilding a Brembo-based 4 piston caliper runs around $100 for seals, per caliper, plus labor. I think you'll find you can buy new calipers from a discounting Porsche dealer for around $400/pair. Something to consider when looking at used $200/pair calipers. Granted, a rebuild may not be needed for many thousands of miles, however, if you bought new, while the cashflow is obviously different, it would be a longer time before a rebuild would be needed.

PC2

Got them off of eBay from LA Porsche. $250 per set.

nine64

Peter,
my came with matching set and it's more like the lower one in your picture, it have Porsche painted on it not casted.

joey bagadonuts

Peter,

Those look right. Here's a pic of some four pot 964 calipers (from Bill Verburg's excllent pelican website). If you have trouble matching the numbers, you may want to measure the piston diameters. Specs included in Bill's brake page.

PC2

Joey,

I did that and the numbers were off. I measured 32mm for the lead piston and 36mm for the trail piston. While according to Bill's site the lead is suppose to be 28mm and trail 30mm. So either I'm not measuring it right or I don't have the right parts.

SIGH.........I guess buying brake calipers from a junk yard wasn't that great of an idea.

bhensarl

Pete,
I've got an 89 C4 and the "Porsche" logo cast on mine. Let me know if you want to know anything else.
Brian

PC2

Brian,

Can you tell me what the casted part number is on your caliper? I believe they are the same as the 92+ c2 rears. Thanks!

Arjan B.

Peter,

I bought in 2002 2 used calipers for the right side of the car. Last November I discovered that the caliper rear right had 2 more bigger sized pistons then the left side. Sombody came up with some exeellent diameters odf the calipers. I think it's in my service topic somwhere. I changed my rear right caliper by the right one, the guys I bought it from made no point of that after such a while, they shipped the right onde to me. There are more then one 4 piston calipers which fit on a 964.

As I see your picture, you have two different calipers, as long the diameter of the pistons are the same, it will be ok, but I would not be happy with it........

Arjan B.

Peter,

I found a picture of the rear caliper, the different piston sizes............

PC2

Thanks Arjan for the pics. After doing some research I found a picture of the pistons and realized why my measurements were off. The top (exposing part) of the piston is actually 4mm smaller than the body. That explains why I got the 32mm and 36mm. So adding 4mm to my measurements gives me 36mm and 40mm which confirms the calipers I recieved are for the front. First thing tomorrow I'm sending these calipers back to be exchanged.

Thanks everyone for the help, although if anyone can still provide me with the correct Brembo part numbers I will be very grateful.

PC2

During my research, I came across this excellent DIY write up on caliper rebuild. It should come handy one day. http://vista.pca.org/sch/tech_articl...er_rebuild.htm

Thomas Linser

Folks!

I always thought that C4 caliper could not me fitted on C2's since the the braking system of the C4 is a preload pressure system an that of the C2 a classical one! Someone can telle me if one could fit C4 caliper to a C2?? If yes that would be great knews to me since I always wanted to do the upgrade, and...C4 calipers are easyer to find over here!!

Thanks for any input

Gruetzi Thomas

Bill Gregory

Thomas,

The C4 rear caliper is the same as the C2 1992+ caliper, although, as you point out, the hydraulic pressurization systems are different between the two.