Inoperative rear brakes

[metalmacguyver]

About the RABS, I was playing around in the snow and I did manage to make it work. I had to stand on the brakes and when it did work, it only pulsed every 1.5-2 seconds. I was not impressed. That rate of response is not sufficient to provide much safety.

 

[MAKG]

Nope. The wife is out of town, so I'm on toddler patrol.

metalmcguyver, I thought the spec was nearly 10 Hz. Are you sure yours was working?

 

[MAKG]

OK, plugged ABS valve confirmed. Thanks, jspafford.

The cheapest price by far is autozone.com. $100 + $60 core. My usual Ford dealer (Mission Valley Ford Truck) wants $198 + $100 core. The gold plated Ford dealer (Palo Alto Ford) wants $275. So, it's on order.

 

[metalmacguyver]

I could definately feel it working but it was slow as heck. It definately surprised me how slow it was working.

Its not something that has me worried though.

 

[Jspafford]

OK, plugged ABS valve confirmed. Thanks, jspafford.

The cheapest price by far is autozone.com. $100 + $60 core. My usual Ford dealer (Mission Valley Ford Truck) wants $198 + $100 core. The gold plated Ford dealer (Palo Alto Ford) wants $275. So, it's on order.

No need to thank me.

I was hoping for your sake I was wrong. Those valve are extremely overpriced. Looks like you were able to find one cheaper than I was quoted.

If you don't mind my asking, how did you determine it to be bad?

 

[MAKG]

If you don't mind my asking, how did you determine it to be bad?

Block front wheels. Release parking brake and roll back onto blocks. Push driver's seat all the way forward. Install large 1/2 inch breaker bar between seat and brake pedal. Remove front driveshaft. Loosen output fitting from RABS valve and note if it leaks. If not, do the same to the input. Tighten both back up.

A bad valve leaks at the input but not the output.

It's basically the same test I did on the master cylinder to determine it was good.

I also found a post in Ford Truck Enthusiasts that described the EXACT same problem, and the owner ended up disassembling the valve to find it rusted solid in the closed position.

 

[MAKG]

OK, now I feel like a fricken newbie.

I put the new RABS valve in. It leaks out the input fitting. I figure there is a piece of dirt in the seat, so I take it apart and blast it with Brakleen. No improvement. Though I can't see the seat with the valve installed, so it's possible I didn't get all the dirt out. So I swear a bit about FN remanufactured POS's and put the old valve back in, figuring I'll return it and take care of it later. Except I CROSSTHREAD the FN fitting. I haven't done that in years. So I feel like a rank newbie. Now the Exploder is down because the brakes piss all over the driveway.

I figure I'll try again in the morning. I'll remove that upstream brake line entirely (it just goes to the master cylinder, right?), so I can make a decent seal without a contortion. Hoping beyond reason that I just didn't get it right the first time. Is there any kind of sealant I can put in there that I wouldn't mind in a braking system? I've entertained the idea of putting a little aircraft sealant on the seat with a toothpick. Yeah, I know. Stupid idea. Is it a good idea to replace the fitting? I have a flaring tool, but it's in the box and it's something I've never done before. I figure I'll just cut the old seat out and flare it again. Is this a bad idea on an 18 year old brake line that appears to be in pretty good condition? I suppose I could just replace it with a new line....

I guess I need a little more Special High Intensity Training. No, strike that. I have quite enough S.H.I.T. going on right now, thankyouverymuch.

Dangit.

 

[metalmacguyver]

SHIT happens....

 

[flyingbrick]

I know you can get hydraulic ''Teflon'' tape that is good for about 10,000 PSI. i have some rolls in the shop. If you only put on a single layer on the threads you would be OK, if nothing else.

 

[skippy]

cut it,reflare it.

 

[Evan]

Yes, that line goes right into the MC.

And if you have any worries or problems reflaring the line, a new one should be real cheap. Standard 3/8" fitting line. Then you will need an adaptor fitting to go 3/8" into the wierd size that the MC takes for the rear output. Adapter and new line should run < $5 alltogether.

It happens to even the best of us, but it really sucks when you make a newb mistake that results in more time and money, plus a downed vehicle.

 

[skippy]

cut it,reflare it.

i just looked at an old brake line i had laying around,you will need a double flare kit.

 

[MAKG]

I ran out of time, so I had to take it to a local shop. Got it done in 3 hours while I hauled a bunch of junk to the dump (something else that had to be done RIGHT NOW) using the Chevy.

Simple crossthread, both times. Expensive stupid mistake. And I even made it to the 5PM gig yesterday.

But now the truck works. The brakes are substantially better than they ever have been. The vehicle no longer slides on the (really steep) driveway even when I back down too fast with the brakes engaged. I have to try not to stop too fast on the highway now....

And HOT DAMN those 10 inch rear brakes are enormous.

 

[skippy]

cool,glad you got it.

thanks for sharing.

 

[MAKG]

S H I T

It's leaking again. FN repair should have lasted more than two weeks.

And I found out the shop didn't secure the brake line and it was contacting the valve. If this is leaking ANYWHERE but the input fitting, it had better be on them....

So, I'm taking it back. I still don't have the time to deal with this.