OK so after two days researching and rebuilding brakes I have decided there is a good chance the rabs unit is causing my spoungy pedal. So now I need to know if I can buy the rabs unit without 'core' (not even sure what that is?) or can I get a rebuild kit for the unit. If so does anyone know the part numbers for either unit or kit?
Cheers, Frank.

 

RockAuto has them for around $200 without the core and they do ship overseas.
However if you suspect that is the cause of a sinking pedal then before you replace it do this. On the end of it you will see a large hex bung. Unscrew that (against spring pressure all the way) and remove the spring from the chamber (no fluid will come out), then replace the bung. Pump the pedal a few times to fill the chamber. If the brakes are now good then you can either leave it that way or replace the unit. If brakes are no different then refit the spring and look elsewhere.

 

Does any one have an opinion on the rebuilt units. The new motorcraft one is $320us plus shipping but I can get a raybestos rebuilt for $150 plus shipping. Is raybestos a known brand or are they crappy. A1 cardone also do a rebuilt for $200 plus shipping.

 

Raybestos are well known brake parts manufacturer. How good they do with rebuilding ABS HCUs I dunno tho. But I'd really try to avoid that A1 Cardone stuff, I've had several master cylinders and brake booster remanufactured by them be bad right out of the box - if they can't fix simple mechanical things, I personally don't feel I can trust them with something that involves electronics... You know you can always use a manual brake bias valve, you can pick a good one up for as little as $30-something US, and then you're the one in control of your rear brake line pressure. Tho I'm not sure if that'd be legal down under.

 

anyone have pictures of the RABS unit?
Also, more info on the overhaul kit like where it can he had, pictures of the parts included and pricing?

I am replacing everything but the calipers (I'm rebuilding) and the RABS unit (I have not decided yet what to do with it).

 

I haven't been able to find any sort of rebuild kit from anyone. Prices I quoted above for new and rebuilt units are from ROCKAUTO but Y2K FORD PARTS were about the same. One guy said they were pressed together and as such you need special gear to rebuild them but I dont know how true that is. I would suggest doing the test above and if your unit is good leave it alone. If you search this forum under "soft brake pedal ' there is some good posts on testing brake sysems to diagnose the difference between rabs and master cylinder failure.

 

Well, I have to get this done in one weekend.
How easy is it to get the old brake fluid out and flush it clean?

I'm going to be going to DOT 5 fluid and want all the old crap fluid out of there.

Nobody has any pictures?

I have a habit of rebuilding non rebuildable parts any time I can, and if I fail, it needed replacing anyway!

 

Not true.
I found some pictures and they are clearly bolted together with 4 bolts, surrounding the big one that I assume holds the spring mentioned, with a square flange around the middle.
If it bolts together, it can be taken apart.

 

I'm willing to bet that with all the wheel cylinder and master cylinder sizes that were offered through the years, finding piston seals that would fit the RABS for a rebuild should be nothing more than an issue of looking up and finding the proper sized part in a parts book.

I just need to find it quickly after tearing it apart!

 

Archangel, You and me on the same page bro so keep me updated on parts and rebuild. I would like to take mine apart but with parts taking 10 days to get here I would have to buy a new one just in case I couldn't fix the old one. I have also seen the bolts since I last posted and will pull mine apart if I get a new one soon just to see whats inside/involved. I read an article that said it is the needle and seats that get damaged not the piston seals so I am wondering if they can be repaired/replaced. I would much rather repair my own gear and I fab as much as i can but living in oz means no nipping to the pick-a-part when things turn to s@#t.

 

I'll be taking another trip to the wreckers on Sunday.

The wife will bitch as I thought I had everything I needed and she is not expecting another trip.

 

my girl freind loves to go junk yard with me

 

ARGH!!!!!
YOU LUCKY DOG!!!!!!

My daughter won't even go with me any more!

 

y wont ur daugher she disccovey boys to ur dislike lol

 

First things first.

THEY ARE REBUILDABLE!!!

1: Find a unit that is caked with oil and dirt. If not, it will be rusted badly.
2: See if the brake fluid looks ok in the master cylinder, if not there might be a serious internal rust issue. This is also the reason I prefer DOT 5 fluid. No moisture, no rust.
******
SERIOUSLY, DO THIS!
3: Pull it apart in the wrecking yard to verify it's not all rusted out on the inside before you plunk down your cash as a rusted out unit could be worthless.
******
4: Do not use brake clean on the seals as they will swell up badly. Just wipe them down, lube them with brake assembly lube and put them aside to be reinstalled after the brake clean has dried off the hard parts.
5: If you have access to brake fluid compatible seal selector kit, you are in good shape.


The fluid in the 1994 I pulled my unit from was not too bad, but there was still some rust in it.

When you pull the big 1-1/4 nut there will be what looks like a Stainless Steel spring against an Aluminum piston with a seal seated in the outer surface. My piston was blue and it was a little tough to get out, but I used a snap ring remover set up to open as I squeeze to grab the piston on the inside and pull it out.

The 4 bolts that hold the 2 housings together use a 3/16 Allen wrench.
The brake line fittings that the brake lines go into are 5/8 and 3/4 inch I think.

When the two housing halves come apart, the electrical parts will slide out, but the seal on the white plastic collar is tight, just gently push the part where the wires come out of the unit inward and it will slide far enough in to take out the metal part that is captured between them.

Under the metal part that is held in by the plastic electrical parts is a small spring, a thin brass washer and a shuttle like thing with 2 longitudinal slots 180 degrees apart running the length of it.
The tube it rids in is where I found most of the internal crap built up.
I did not pull this tube out as it was so tight, I felt that the seal holding it would cause trouble getting the tube back in.

I also did not pull apart the internal parts of the metal housing that was in between the electrical parts.

I sprayed and scrubbed everything, and used the wire wheel in my bench grinder to get the hard crap off. Don't forget the bleeder as it will be full of crap that falls off the engine.

Brake assembly lube helps prevent corrosion so I used it EVERYWHERE!

I feel confident that my rebuilt RABS unit will work perfectly, and if there is any leakage, it will be the seal on the white plastic where the wires come out as I could not remove the seal and it did get some brake clean on it.

I will tear apart all the things I did not take apart the on the replacement unit next weekend when I pull the one that is on my truck now.

If I had a digital camera, I would have taken pictures.