• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

PDWA De-Mystified

Share this page

Brosky said:
There is brake fluid in there if the seals leak
Click to expand...
True. But the same thing is true of the master cylinders, and those seals move all the time. The PDWA seals should last much longer, since they don't normally move.

The switch is not designed to hold pressure at all, it's not internally sealed. So, if the seals in the PDWA leak, you can expect to lose brake fluid.
 
Brosky said:
I'm going to order a new plastic fitting from Ford and pick it up when I take my Taurus in for service next week. The old switch was not stuck and the threads were very clean, but I'm not taking a chance, even though I'm switching over to silicone fluid when the new brake system goes in.
Click to expand...

Ford? Are we talking about the switch, or just a seal?
 
The Ford part number for the same exact switch is: #C8AZ-2B264-A. I got that information here: https://www.britishcarforum.com/bcforum/ubbthreads.php/ubb/showflat/Number/332504/gonew/1#UNREAD

The part number for the Moss kit with the seals and copper gasket for the big end plug is: # 181-995.

Randall, I agree with you somewhat. Isn't there constant pressure when the Brakes are applied, to both the front and rear of this piston? When the pressure is decreased due to a leak, the piston moves either forward or back and the switch plunger slides up into the housing and makes contact, then the brake light comes on. As long as there is no loss in pressure the piston never moves.

I was simply stating that the only way possible for the switch to leak, is if one or both of the internal seals leak and allow the fluid to come up through the plunger shaft and out of the switch.

Look at the junk that is built up on these two seals. One cracked when I took it off and the other is as hard as a rock. It was only a matter of time for these to start leaking.
 
Don,

No, I do not work for Ford. I had over 25 years in the car business. That was enough for one lifetime.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] Look at the junk that is built up on these two seals. One cracked when I took it off and the other is as hard as a rock. It was only a matter of time for these to start leaking.
[/QUOTE]
Opps, misread the post. Yes they were on the verge of leaking, but just think you won't have to fix for about 30 years. Well maybe 20.
 
TR3driver said:
I lost a previous TR3A (which having single-circuit brakes of course had no PDWA) due to total brake system failure. Hard line rotted through from the inside, which I didn't discover until I was going down a very steep hill into an underground parking garage
Click to expand...
Oh great, now you have just given me a reason to be paranoid about the only critical bit I haven't replaced on the Herald.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Oh great, now you have just given me a reason to be paranoid about the only critical bit I haven't replaced on the Herald. [/QUOTE]

That's why I'm replacing all of my brake lines. After 33 years, they owe me nothing. If I have it for another 33, let the next guy worry about them after me.
 
Paul
Where did you get your repair kit?
Also, it sounds like a Ford Switch will replace the original, what year and model?
Thanks
 
Norton,

The part number for the switch is a few frames back and the kit came from Moss. Part numbers are in pictures.
 
Mark- Got my part from ford.Might have to order it.
 
Back
Top