Brake pressure failure switch.

[ecurie_ecosse]

Hi all,I've just replaced this switch but fliud pours out of it when brake pedal is depressed. Is there supposed to be a washer on this? If not how do you stop the leak? /ubbthreads/images/graemlins/confused.gif

Stuart,(covered in brake fluid)

 

[jlaird]

No washer, bet you cross threaded it or it is not tight.

 

[ecurie_ecosse]

I'm guessing,cross threaded = new switch. /ubbthreads/images/graemlins/eek.gif /ubbthreads/images/graemlins/rolleyes.gif
I'll try tightening it tomorrow.

Stuart,(all cleaned up)

 

[DrEntropy]

Clean the car too! Brake fluid is *VERY* unkind to paint!

 

[jlaird]

Might mean new fitting, it is brass and the switch is stee.

 

[ecurie_ecosse]

The switch is plastic.I should have said it was on a '78 1500.
Somehow managed not to get fluid on the paint.Locky me!

Stuart.(not touching any part of the Midget today)

 

[sparkydave]

If the fluid is leaking from the plastic part of the switch (the part the wires connect to), then you've got bad seals on the plunger inside the actuator body. They can be replaced, but it's a PITA to get the big nut off the end of the valve body. Oh, and one thing I've discovered about the PDWA on the '77 and later is that the plunger latches in place if it turns on, so if you're bleeding the brakes using the pedal method, you have to unscrew the switch body (plastic piece) from the plunger to let it snap back. Following the service manual's procedures for re-centering the PDWA plunger won't work. Apparently the design changed, and the service manuals didn't keep up with the change. The old one had a groove in the plunger, but the newer style has a ridge instead, and since the ridge has flat sides it won't center again without removing the switch. If you use a vacuum bleeder as I did, no problem.

 

[ecurie_ecosse]

Ah well,I'll strip it down and find out if it is. /ubbthreads/images/graemlins/rolleyes.gif

Stuart. /ubbthreads/images/graemlins/cheers.gif

 

[ecurie_ecosse]

Well I finally fixed this leaky thing.Replaced the o rings in brass valve,found that I'd broken the thread off the new failure switch,managed to get another and put it on correctly this time.No leak!!! /ubbthreads/images/graemlins/thumbsup.gif

/ubbthreads/images/graemlins/cheers.gif

Stuart.(Lying in last place in the rally)