Lemming

Anyone have the wiring diagram for the boxster pump?

Eric_k

Tim - check page 45 D-16 here:
http://www.cannell.co.uk/Boxster_Man...%20To%2045.pdf

TonyG

While it's a Boxter pinout diagram, it's for the incorrect ABS pump.

Notice the 3 rows of pins. That pump cannot be used as a stand alone.

You need a 2 row 986 Boxter pump.


TonyG

333pg333

How'd the new brakes go yesterday Tony?

Eric_k

I'll preface this by saying I'm no Boxster expert, but as that pinout diagram shows a 1996 print date, I think it applies to early Boxsters. One row of pins is TC (traction control) specific so possibly they don't exist on non TC cars. Maybe you could post a pic of your connector?

When you said 3 rows of pins I thought you were referring to the ABS with PSM pumps. These have a different 3 row connector. As shown here:

Lemming

This is what the 986.355.755.00 unit looks like. Looks like pins 1-26 are similar, 27-31 are not on the unit I have. Is it likely that the assigments for 1-26 are the same?

TonyG

Hey

Sorry for the late reply. I've been extremely busy the last couple of days. And... just noticed my belts are expired. Great. 6 days before the next event!

I had a brake line leak at the banjo bolt at the caliper. Fixed that, then I think the ABS stopped working. Not sure why.

Today we are going to get a light output from the pump to indicate the status of the ABS.

Not sure what the problem is yet because we haven't hooked the computer up to the ABS. I might have damaged a sensor when I swapped out the steering knuckles or somehow the brake fluid leak might have screwed up a sensor... who knows.

We have the ABS pump diagnostic wired to the correct unused OBD2 port for the factory computer, so the Porsche diagnostic software connector just plugs up into that.

Anyway... I can say that without the ABS working, the GT3 brakes with the Boxter rear proportioning valve is too much rear brake (not by a huge amount, but too much for the race track). I'm probably going to install the Wilwood brake proportioning valve (the same one that I have been using for years prior to this ABS and big brake upgrade) so that in the event the ABS shuts down in a race, the brake proportioning is still good.


I'll report back in a couple of days after I get the changes done and back out on the race track.

TonyG

TonyG

I'll preface your preface... by also saying that I too am no Boxter expert :-)

The pump shown in your image is a 3-row pump. But after digging through a pile of pumps at my friends shop (and we're talking about a LOT of pumps.... ) I can tell you that there are several different 3-row pin configurations. But they are still 3-rows rather than 2-rows.

Looking the PDF link you posted, 45 D-16 shows the receptacle that clearly has 3 rows of pins on one side.

I was told, and I do not know this for a fact, that the pump had to have 2 rows of pins.

And my pump does have 2 rows of pins and is like what Lemming posted (see his pic of a 2-row connector).

Which I could be of more help.

TonyG

Eric_k

I would bet they are the same. Since the row with pins 27-31 are labeled as:
" * Only on Vehicels with Traction Control(TC)".
Porsche may be using one diagram to cover several variations of the pump.

Olli Snellman

I suppose there are at least one another pump which can be used. Part number 986.355.955.00 is the superseded number that was: 986.355.755.00. Pin diagram is exactly the same.

Tony, check out original 951 proportioning valve. We have used it with the same caliper setup you have.

Oddjob

Does the Boxster ABS brain not have the problems of the 996/997 street ABS, when used on track cars?

333pg333

Ice mode?

Lemming

Jim, what is the problem with the 996/997 street abs?

Oddjob

Heard guys discussing/complaining about it a few years back. ABS faulting so it would keep the car from stopping (like sliding on ice). May have been an intermittent fault, or caused by certain conditions. Remember some discussion about heat/temp. Thought PCA was considering allowing updating the ABS units to the motorsport units as a safety fix. Didn't pay much attention to any of it, as it didn't affect me.

Probably some discussion on the racing or 996 forums about it. Just wondering if the boxster ABS did not have the same concerns.

(EDIT, add): Here's a thread on it:

https://rennlist.com/forums/showthre...ferrerid=15894

Eric_k

Here is some more info based on a pump I have in my hands. 996.355.755.03 is a "2 row" pump. The connector on the pump side is 2 rows. The harness plug is "3 rows", the 3rd row unused.

The pin diagram in the document attached above is clearly of the harness plug and not the pump side of the plug. I'm pretty confident now seeing that a 2 row pump has a 3 row harness plug that the pin layout is correct.