1992 f150 daily driver and adventure rig.

[greengreer]

I have thought about the adjustable proportioning valve, I would really like to take try and clean out the rabs valve though before I go to that. I am sure it is dirty as can be, I cleaned the resevoir and sucked all of the nasty old fluid out everywhere but I am almost certain there is some gunk in the rabs valve. I believe you can pull the plug out and clean it with brake cleaner and maybe replace any necessary orings, maybe that will helps. So does it use the vss sensor to activate? Like I said its a very different issue than what I had to deal with on the 350. That truck had the abs light on and made a clicking noise when the brake was applied. I will have to figure out something before snow comes, it is far too easy to lock up the rear brakes on the f150.
Also thanks for confirming what I suspected with the master and booster taking a dump at the same time. Brakes are good...

 

[AFBronco235]

Have you tried taking apart the rear brakes yet? The clunking could simply be from an incorrect install, which is pretty easy to do on these. It could be any number of pieces in there not assembled correctly. My best guess is one of the balancing cables isn't routed correctly in the brake and its also affecting your braking pressure. It could also be causing your ABS issue as well. I have literally taken apart and reassembled over a hundred different drum break styles and if you don't get everything just right, it just won't work. One of the biggest reasons to swap to rear disk brakes IMO.

 

[greengreer]

Haven't messed with the drums yet. Mostly because I hate messing with drums. I do wonder if they are adjusted correctly. I don't have a clunking noise on this truck, mayne you meant the clicking noise of the rabs valve on my f350 I mentioned.
Ford's rabs system is pretty crappy imo, honestly I am thinking an adjustable bias valve might be the ticket. It doesn't function like true abs anyway and I am confident in my ability to not just mash the brake pedal.

 

[underdrive]

I'll have to disagree on the Ford RABS not working very well, I think it does quite well for what it is. IMHO the perfect setup would be the load-sensing valve some '80s trucks had to adjust line pressure based on how much weight there is on the axle, and behind that a RABS unit to handle lockup in slippery conditions.

In any case, if you pull the big cap off the end of the RABS unit you gain access to the back side of the accumulator chamber piston. With the cap off the spring that pushes the piston (so it can purge the chamber once you let off the brakes) can be removed, or more likely it will try to fly out. Once the spring is out you should be able to pull the piston out and clean the whole chamber nice and good. Additionally the RABS has two solenoid-actuated valves - a normally-open isolator valve to cut off brake pressure from the master cylinder during lockup, and a normally-closed dump valve to release some of the pressure already in the line out into the accumulator chamber. If the isolator valve is stuck open then whenever the dump one opens your pedal will sink way close to the floor (but this will only happen during wheels lockup), if it's stuck closed then you have no rear brakes at all. On the other hand if the dump valve is stuck closed then it will not release any pressure out and wheels once locked up will not start rolling again, whereas if it's stuck open then EVERY time you get on the brakes the pedal will sink way low and rear brakes will be weak. Seems to me you either have a dump valve stuck in the closed position, but here's the thing - the first time the dump valve doesn't open when commanded to and the electronic brain does not see the wheel speed increase it expects to see (via the VSS, yes) the system will go into bypass mode and disable altogether reverting your rear brakes to full-manual operation as if you physically bypassed the RABS unit. Light will be glowing on the dash, as long as it's not burned out - pay attention to the light when you first turn the ignition on, if it comes on and then goes off then it's working fine, and the first time the wheels lock up it should come back on and stay lit for as long as you don't shut the truck off.

 

[greengreer]

Thanks for the great advice, I will definitely be cleaning it out before snow begins to fall. Working on changing the sector shaft seal, it has been making a hell of a mess lately and I finally got around to fixing it. Not much room to work with the front diff right there.

 

[greengreer]

Been a while since I've updated this.
In that time I have been really enjoying the old f150. I have put 5k or so miles on her. Since my last post I have replaced the fuel pressure regulator along with a few vacuum lines. Truck runs and starts much better, as basically raw gas was getting sucked into the manifold from the fpr. I have also redone the exhaust to get rid of the shoddy dual exhaust the previous owner cobbled together. I went with a y pipe, no kitty, into a big walker truck muffler with a turndown, all 2.5". It's nice and compact and tucked up better than factory. It's still maybe a little louder than I care for but its much better and there is no drone in the cab. Also I get no cel's anymore even without the cat. Anyone ever remove their A.I.R pump? Just seems useless to leave it on.
Still needing to get some shocks, and find some yakima crossbars to complete the roof rack system. Also I think I've settled on a truetrac for the 8.8 when funds allow.
Love the simplicity of the truck and how nimble it is for a fullsize. Goes anywhere from the grocery store to logging roads without batting an eye.

 

[underdrive]

Yes you can do away with the air pump. Never did like them things, they're just fine when new but at the age even the newest of these trucks are at now they can be prone to seizing up (and naturally that takes your belt out). Reman replacements are both expensive and low quality, waste if money IMHO especially since one doesn't actually need the air pump to pass the sniffer emissions test, let alone if there are no kitties under there to begin with. I say if possible lose the thing and run a shorter belt. Do consider adding a cat though, universal aftermarket high-flow cats are quite reasonably priced these days and (if nothing else) they do a marvelous job of taking the raw fuel smell out of the exhaust fumes.

Oh, and regarding the differential - I'd keep the factory posi and just tighten it up a bit if needed, and consider installing the True-Trac in the front axle instead. IMHO unless you have lots of weight in the rear with these trucks it's really not hard to reach the point where both your rear wheels are spinning and one of the fronts is too but truck still ain't moving. Front-axle traction device will help fix that, and the True-Trac is probably the best setup for that particular use short of an on-demand locker.

 

[greengreer]

Thanks for the true trac tips, problem is that the rear diff is open so I think the rear will be done first, I would love to have a selectable locker up front but I don't think it will make the budget. I was really considering adding a cat when I redid the exhaust, I certainly still could. Do the new cats still require air injection?

 

[greengreer]

Linville gorge back in August. Having 8 or 9 feet of canoe hanging out the back is what's really driving me toward yak racks.

 

[95C1500]

I like the truck! Keep up the good work

 

[underdrive]

Oh I thought it was factory LSD in the rear. Nevermind then, proceed with the True-Trac plan. Also no, cats do not need air injection, you're in the clear there,

 

[greengreer]

Rained out of work today so decided to go ride a local trail. It's actually a county road but has been unmaintained for a long time. The pics don't do it justice. I was traveling alone and didn't want to stop on the technical stuff to take pics for fear of getting stuck. Had a blast and the truck exceeded my expectations. Only lost traction once, which required a little more speed on the second try on a small slick climb. Drug the rear bumper lightly twice although I think it was just the bottom of the hitch ball. Ran the trail with 30psi front and rear with the old bfg ko's (about 1/3-1/4 tread left). It has been raining alot and some of the holes and creek crossings were up to the rockers. Need to go back with some company and hit play around a bit more. Also need to bring a trashbag next time, place was littered with cans. Don't get me wrong, I like my beer too but damn!
Good to know about the newer cats not needing air injection. Thanks!
Also checked to see if my tirechains from the f350 fit, nope. Looks like I'll be purchasing a new set here soon. Looking at Rud's. Anyone have any experience with them?
Also found out bronco graveyard carries doetsch tech 8000 shocks for 1.5" lift which may work out well. I haven't seen to many reviews of their shocks but for half of what bilsteins cost it may be worth a try, although you get what you pay for usually...

 

[kojackJKU]

you should see if there are Monroe reflex monotubes available for it. They have a lifetime warranty and they ride and perform awesome. I have them on three vehicles now!

 

[underdrive]

Also checked to see if my tirechains from the f350 fit, nope. Looks like I'll be purchasing a new set here soon.

Why don't they fit, too small for the 33s?

 

[greengreer]

The reflex's look like a good shock, however I am wanting something slightly longer than stock to account for the taller coils in the front. That's why I am leaning toward the doetsch techs.
Yes the tire chains are too small. They are made for 235/85r16 but have also fit 265/75/16 with room to spare. They didn't fit my 285/75/16 or these 33x10.50x15. I could probably add a link or two but I need them for my f350 so I might as well just buy a pair for this truck.