I'm trying to perform the following test:

"The rwal valve is pretty easy to test for internal leakage. There is a rubber plug in the end of the accumulator. Remove it and stick a straightened out paper clip in the hole until it bottoms against the back of the accumulator piston. Have a friend step on the brake pedal. If the paper clip moves the dump valve in the Rwal valve is leaking."

I was under the impression that the RWAL valve was located on the driver side frame rail above the rear axle. When looking at this unit on my truck I do not see a rubber plug anywhere to remove to perform this test. Am I looking in the wrong spot, or just not looking hard enough? Any help would be greatly appreciated.

 

Your "car" meaning your Mercedes? Or your truck?

 

On my truck, sorry.

 

Ha ha, makes a difference.

If I recall correctly, it looks kinda like a brake bleeder on a little valve thing. But I've never messed with it and not even looked at it for a long time so hopefully someone that has will chime in.

 

I saw what looks "exactly" like a brake bleeder port on this rear abs module (on frame above rear axle), but I just assumed that it was in fact a bleeder port. Can anyone chime in if this is in fact the thing I'm supposed to be testing, and not an actual bleeder port?