Anyone changed their rear drum brakes to discs? I've done it with my 94 explorer, and i was wondering if the axles are the same, just swap the hardware like the explorers are. Any help woudl be appreciated. Thanks


Dube

 

I wondered about doing this too as my '97 was built too early to have the rear discs... Maybe a salvage yard would have a wrecked one for all the little bits and pieces...

 

Well, I know the 95-01 explorers rear axle with disc brakes is a dirct bolt on to the 91-94 as a complete unit. You only need to get new e-brake cables for the newer ones, and you're in business. I was wondering if the 99up with disc rear axles are the same in this manner. Any help?


Dube

 

I am very interested in doing this also. Main problem I see is the rear wheel ABS the 97 we have came with... and ideas?

George

 

Aren't the brakes computer controlled? If you change the rear does that cause computer issues?

 

The ABS shouldn't cause any problems. Both the disc and drums use the sensor in the top of the diff housing and it doesn't know what's at the end of the axles.
I would assume that the brakes would just be a bolt on swap as both discs and drums were available. A wrecking yard might be a good place for info, or a patient partsman at your dealer. They could look up the rear end housing and axles and see if there was any difference between the 2.
You might also want to check and see if there is a difference in the master cylinders. They might use different size bores.
The park brake cables are different but should be an easy swap.

 

Thats some great info Dave, however, I think I'll wait until I find someone that actually did it. Unfortunately the trucks are still very new and finding them at the wrecking yard is next to impossible.

George

 

I am in the middle of a rear disc conversion on my 1999 F-150 XLT 4WD (Oct 1998 production w/4 wheel ABS) with a disc brake system off a mid-year 1999 F-150 4WD. While searching posts seems like there is a alot of interest in this conversion. Either folks are doing it and not talking or I going to be the ginnea pig on this one. Once complete and fully functional I will post my process and findings.

One of the remaining riddles I want to run to ground is regarding the ABS ECU module. I have spoken with several folks who sell aftermaket rear disc kits as well as the folks who rebuild the ABS units. The overwhelming consensus is that there should be NO problem with using my existing 4 wheel ABS system. I do see that Ford has (2) different 4 wheel ABS units. One for the 2 wheel disc (w/ rear drum) and another for the 4 wheel disc. Does anybody (RacerGuy?) know what the difference is between these two ABS ECU's are (besides price)? While I have bought off that my existing ABS ECU module will (most likely) be perfectly fine, does anybody know if the 4 wheel disc model will drop in? Specifically, are the connections to and from the pump the same as well as the connector on the harness. Also what functionality do I loose / jeapardize by keeping my existing ABS ECU?

 

I always disliked the way the truck stopped - seems like no matter how well I kept the rear drums adjusted they still sucked!. I would typically only get 20 to 25k out of a front set of pads. Sometimes only 15k. Due to my familiarity with the task, I was doing front brake jobs in less than 30 minutes.

Did alot of 'research' and found there were some aftermarket rear disc conversion kits. I wasn't really impressed with any of them - to the extent that I would put down the money they were asking. Besides cost, the biggest turn away for me was the fact that they either (1.) used parts that you could only purchase from one place which means they get to name the price and timeline to furnish replacement parts (2.) used a hodgepodge of parts from several makes and models (reminded me of the Johnny Cash song). My overriding decision to find a Ford donor, of the same vintage / model, was so I could go into the local parts place and get parts I need without issues from points (1.) and (2.) above.

After looking under some trucks in parking lots and junk yards I found that the 4-bolt mounting hubs on the drum axles are difference from the disc axles. It is possible that a competant rear end shop could swap these hubs out (cut and weld). If you went this route you would need to find breaklines and all the parts from the backing plates out. Still need a donor axle. However, if you were in a senario where you found a donor axle but the gear ratio was wrong or the axle was damaged this "could" be an economical solution.

I found a donor axle (same gear ratio) from a late model 99. My truck is an early model year 99 and when I ordered it, disc was not available. My truck did come with the 4-wheel ABS w/ rear drum. I had some concerns over how the swap would effect the ABS system. I called a bunch of ABS service places because I was comtemplating changing the ABS control unit. During my 'research' I found that the ABS control units are different between the 4-wheel disc and 4 wheel ABS w/rear drum. All 4 places I called around the country told me not to worry about swapping the ABS unit that it would probably be a waste of time and money.

After some extended negotiations with the local wrecking yard, I paid $250 with exchange of my drum rear axle. They originally wanted $550. The new axle came with all the parking cables (which lucky for me came from the same size wheel base truck and saved me the expense of purchasing them). When I got it home, I opened up the cover to find that the limited slip clutch was in bad shape. Opps. Maybe not as good of a deal as I originally thought. Limited clutch being shot was evidenced by several dime sized tabs in the oil. I was able to pull the posi unit and took it to a rear end shop and had it serviced for $150.

Replaced both rotors, calipers and pads. Bearings, caliper hoses, brake lines, and brake cables were in good shape and suitable for reuse. I replaced the outer seals, refilled with new gear oil and friction modifier. Needle gunned (a.k.a slag buster) the rust and painted it with a high quality black gloss paint.

Installed and it bolted up perfectly - no issues. Also went ahead and changed out the master cylinder as well to the larger one that is paired with these axles. If memory serves me correctly its a 1-3/16" bore versus the 1-1/8" with rear drum. I did go for a test drive before changing master cylinders and it was much better than the drum. Was even better with the larger master cylinder.

Have had rear disc now for 7-months and my only regret is not doing it earlier. I dumped about $750. Truck stops great now - stops on a dime and gives me a nickles worth of change. I had about 15k on the front pads when I put the axle in. The other day I checked the pads now at ~20K on the fronts and they are in great shape. I suspect that I will easily hit 40k with them.

 

you do realize you're responding to a 7 year old thread, don't you?

 

who cares? its still info!

I put a 9.75 rear out of a 02 4x4 in my 97 its got discs and stops my truck like an indie car!

 

REALLY!!! im about (hopefully) to get a 97 4x4 f150 that has rear drum, and i was wondering about a rear disc conversion. so really all it boiled down to was swapping out the whole rear axle and upgrading the master cyl?

 

Replaced both drums, calipers and pads. Bearings, caliper hoses, brake lines, and brake cables were in good shape and suitable for reuse.


you did mean you replaced both rotors right? i was a lil confused...

 

just the rear was changed, I was told that the brakes were a low pressure disc system so no mods to the braking system was going to be needed. In fact I beleive that to be true, im a sceptic becouse Ive done older car swaps and street rods but I did it any way. It nearly puts you in the windsheild now when stopping has great pedel feel and the anilock works perfect with it. The upside to my swap was someone allready changed the gears out and added a spool witch makes for fun burnouts lol.

OH wait! you will have to do some emergency brake modds as the cables are differnt between the two, either getting the whole setup up to the peddle or making a new adjustment mount to put both the rear cables to the chassis cable (wich I still havnt done).....

And I need to add my truck is LOWERD and I had to modd my spring perch to move the axle back about 3/4 of an inch to work properly to the driveshaft (later I will get the driveshaft shortened). On a stock height or lifted truck you may have no problems.

 

Yes that is right - typo on my part. Fixed / Edited my post for perpetuity.