rear brake pressure valves.

[Brit-Car-Nut]

I've been looking at them as well. There seem to be 3 inline versions that fit all GM cars: 905-952, 905-953 and 905-955.

Probably need to find the fitment and research the limiting values for the car:

905-952 fits the 1998 Pontiac Grand Prix: 3.1L 189Cu. In. V6 GAS OHV Naturally Aspirated
905-953 fits the 2000 Pontiac Montana - a mini-van
905-955 fits the 2000 Pontiac Sunfire 2.4L 2392CC 146Cu. In. l4 GAS DOHC Naturally Aspirated

They fit other cars in their respective size group, but the 905-955 seems to be for the "small" car group. Cavalier also uses that valve.

There are numbers also listed under ACDELCO.

I found an affordable ACDelco 172-2223 on eBay and ordered it to see what it really is.

Amazon seems to have a lot of people selling the ACDELCO versions.

[dapinky]

Probably need to find the fitment and research the limiting values for the car:

That's what I've been trying to do - but I haven't yet found any details of the pressures in those cars - maybe there is an owners forum where such a question can be asked?

[Brit-Car-Nut]

Any thoughts on how to test each valve and determine the details?

Seems to be a lot of work to build a complete system to get the pressure readings. I assume the bench shown in the Service Guide is watching the input pressure ahead of the valve and the output after the valve.

Maybe a small hydraulic pump like a porto-power?

I will get the one I bought later this week and I will get some lines made up to try to test it.

[cliff]

Great discussion guys, just to add my 2 pence/cents.

On my car, the original limiting valves had been deleted but the 3/15 proportioning valves had been left in. With the original brakes fitted the annual inspection showed these figures: (kgf)

Front L 229 R 241

Rear L 88 R 76

That works out at 72/28

The valves were replaced with the preferred 2/15 type, at the same time I fitted Wilwood front calipers and PNM rear calipers. The next annual inspection showed:

Front L 263 R 261

Rear L 91 R 88

Roughly 74/26, not too far away from 70/30

For valve testing, I am sure Dave will correct me if I am wrong, as far as I am aware, the UK inspection measures the brakes at full pressure. On a recently overhauled system, the valves are very easy to change, just needing a quick bleed on the rears. Anyone with access to the brake testing equipment could do some dynamic testing and give a quick evaluation of the efficiency of the valves.

[Ted]

I've been looking at them as well. There seem to be 3 inline versions that fit all GM cars: 905-952, 905-953 and 905-955.

Probably need to find the fitment and research the limiting values for the car:

905-952 fits the 1998 Pontiac Grand Prix: 3.1L 189Cu. In. V6 GAS OHV Naturally Aspirated
905-953 fits the 2000 Pontiac Montana - a mini-van
905-955 fits the 2000 Pontiac Sunfire 2.4L 2392CC 146Cu. In. l4 GAS DOHC Naturally Aspirated

They fit other cars in their respective size group, but the 905-955 seems to be for the "small" car group. Cavalier also uses that valve.

There are numbers also listed under ACDELCO.

I found an affordable ACDelco 172-2223 on eBay and ordered it to see what it really is.

Amazon seems to have a lot of people selling the ACDELCO versions.

Did you test the ACDELCO valve? Is it ok?

Edit : does some one knows about this http://www.rockauto.com/catalog/moreinfo.php?pk=3388488?