Bled the brakes at 293,957 miles

[sdpatt]

I am somewhat embarrassed to have to say this, but this is the first time I have ever bled the brakes or replaced the brake fluid in my 1991 SHO. I had referenced the owner's manual regarding this issue when the car was young, but I never found any requirement in the Ford manual to replace the brake fluid. Forgive my maintenance omission.

I would also like to say that this is the only time I have ever added new fluid to the brake fluid reservoir. It just hasn't needed any for the 14 years and 293,957 miles that the car has covered. The fluid level decreases when the pads wear as additional fluid volume is required to extend the caliper pistons and returns to the MAX mark when new pads are installed, so I have never had to open the cap to add any new fluid.

I also know that brake fluid is hydroscopic in that it has an affinity to absorb water and I have been concerned with what I have read about this subject. I also know that moisture should not enter the system if it is not breeched. I did not have to remove the cap to check the level since you can see the liquid level through the plastic reservoir. This initial bleeding was going to tell me if I have been correct or not in my water absorption reasoning.

I used a simple "one man bleeder kit" that I had modified with a longer section of larger diameter vinyl tubing to fit over the bleed valve and allow easier positioning of the bottle to allow me to view it while I am pressing the brake pedal. This simple device did allow me to pass one quart of new, DOT 4 fluid through the braking system in the RR, LF, LR, RF order specified by the service manual for the diagonal ABS system in our SHOs.

[NOTE: Added later] I would also like to point out that the bleed valves on the January 1991 brake calipers were sized at 3/8" for the front brakes and 7/16" or 11 mm for the rear calipers. I didn't have to jack up the car to access the bleed valves. I only turned the front wheels to provide an easier reach to those brakes since the front of my car is too low to crawl under. The rear bleed valves could be reached by just laying down and reaching around the aft end of the tires.

On a side note, I read about the Speed Bleeders in other topics and thought that you could make a simple alternative if you were able to couple a check valve with the 1/4" tubing that is normally used for attaching to the bleed valve. Route the tubing to a catch container and move from brake to brake to have a fast, one-man bleed operation.

You can see in the picture below that the 14 year old fluid does not look bad. There were no flakes of rust or any discoloration in the fluid. In fact, I could not tell when the old fluid had been purged and the new fluid was being discharged into the catch container. It all had the color of honey.

The new, higher boiling point DOT 4 fluid should ensure a greater margin of safety for the upcoming track session at the MotorSport Ranch in two weeks. Since I didn't have any boiling problems during track sessions with the ancient, moisture laden(?) DOT 3 fluid, I should have a greater margin to the boiling point than before.

 

[HighSpeed]

That's not bad, the color that is. Shame on you for replacing the brake fluid this late.

On the same note, you didn't want to install some stainless steel braided brake hose lines since you were going to bleed the fluid anyways?

 

[NotSoSlowSHO]

I love it.

14 years old, 300k miles, and the fluid still looks THAT good

 

[AutoSHO]

Hmm, I was considering bleeding mine sometime since I'm getting close to 140k on the original fluid... Maybe I'll wait.

 

[NotSoSlowSHO]

No kidding.

But driving around in a 15 year old taurus makes me wonder more about the condition of the brake lines than the fluid

 

[greenbeanmtx]

So you mean to tell me that you still take the car to track events in Autox it i assume? Scott Patterson i want to shake your hand. That car of yours is an old wise sho for all of ours to follow. I worry about taking mine to the track with 127k on it...... Its maintanance is top notch too.... Oh well. Thumbs up there

Oh ya and the fluid looks great to me.

 

[luigisho]

Can't argue with success as far as the brake fluid lasting that long. I read somewhere that Ford Motorcraft brake fluid while excellent, tends to be more hydrscopic than other high end fluids. Still 300k is quite impressive for all the systems of your car.

 

[AutoSHO]

So you mean to tell me that you still take the car to track events in Autox it i assume?

Open Track, actually.

 

[Fourcats]

Thats great, my kind of maint....Hope this batch lasts as long

 

[rangerj]

I have read two organic chemistry books, and one used "hygroscopic, and the other used "hydroscopic", to define the same phenomina. Any organic chemist out there who can explain the difference, and which one correctly applies to the brake fluid moisture absorbsion.

As SDPatt admits in his thread, waiting 14 years to flush your brake fluid is not the best practice. If you are racing the car, or engage in a lot of hard braking during your daily comute, it is best to flush your brake fluid every two to three years, at a minimum. Pure race cars use very expensive high heat fluid ($70.00 a PINT), and change it very frequently, like every week or every race.

When you do flush your brake fluid, like Scott, use a higher heat range Dot 4 brake fluid. It would also be beneficial to get a brake fluid that is an LMA brake fluid, like Castrol GT LMA, or ATE blue, or ATE gold (used by BMW). Ford also sells a high heat performance brake fluid that is very well rated. Do yourself a favor and DO NOT buy cheap "blue light special" brake fluid. Buy "NAME BRAND" automotive fluids, eg. Castrol, Valvoline, ATE, Motorcraft, etc.

And Scott, as always you are an inspiration. rangerj

 

[Off Road SHO]

Looks good. Don't abuse and you will never lose.


Tom

 

[luigisho]

Ranger I think they are used interchangeably these days. Both refer to water in the base greek and latin languages. However, I believe hygro is more correct. The ancestor of modern English word humid(ity). Check this out http://encarta.msn.com/dictionary_/hygroscopic.html

 

[sdpatt]

Besides my brisk daily usage of the car, I let it loose on "enthusiastic motoring" events such as our LSSHOC Runs and to the road racing course at the MotorSport Ranch.

On the track, I drive the car as fast and smoothly as I can. I will, however, tickle the ABS at the end of the longer straights and as I enter the corners as the lighter loaded inside rear tire is not able to provide as much braking force. I will corner at high enough speeds and apply power until the tires are at the limit as the car drifts through and accelerates out of the corners. This is road course running and not racing, so there is no reason to punish the car for that extra split second of time saved.

The images below show my SHO toying with a Lincoln LS at the MotorSport Ranch. The SHO displayed superior traction in the corners and acceleration on the straights.

 

[rangerj]

Scott,

Your spirited driving is all the more reason to use a higher heat range, Low Moisture Activity (LMA), brake fluid, and flush it more frequently than every 14 years. (tongue planted firmly in cheek, and a bit cheeky at the same time.) rangerj

 

[sdpatt]

I chose a DOT 4 fluid with dry boiling point (BP) of 511F (versus the Castrol LMA dry BP of 450F) and the same 311F wet BP as the Castrol LMA. A quart was only $5.99 at O'Reilly Auto Parts. The fluid should not reach the moisture content that dictates the wet BP with the intended higher change frequency and I should be able to enjoy the protection of the higher, dry BP.

I do intend to change it out much more often than every 14 years ( ) now that I know it is beneficial to change it and that it should take less than one hour start to finish to perform the bleed. I intend to perform a second bleed after I have cycled the ABS during our recent rains.

The brake pedal does feel slightly firmer (I think), but I hope I never find out the boiling point. Since I have never really cooked the brakes, that may be why I didn't see a slug of darkened fluid when the old fluid first traveled through the clear tubing. My brake calipers also still have the original bronze-ish anodized finish.

 

[greenbeanmtx]

I will say it again after seeing the pictures......... i wanna shake your hand.........I got news today that as soon as im done with school ive got a position at a lincoln mercury chrysler jeep dealership about 50 miles away from here.......... So when i start im going to be driving 100 miles a day 6 days a week.......... i ought to catch up to ya then Hearing that yours love to be driven like that with that many miles makes me feel alot better about mine when i run it to the redline passing cars and such. I autoxed mine when i first got it but once i saw how long my es100s last i decided im done using mine on the track......... plus my stock brakes flat suck. But anyways ive got almost 128k on mine........ive got everything 100% on it and updated so i think shes up for the highway commute everyday.

I just realized you live in Richardson, if your ever in the Waco area give me a buzz, id like to see this car i admire and my 93 envies. Im just down the highway from you. Take care

 

[olympic]

Your Texas climate may have alot to do with the good condition of the fluid. Extreme cold and changes from cold to warm(like a heated garage) will introduce moisture into the fluid. I had a flush done on one of my vans a while a ago, it was only 3 years old and had 150k miles and the fluid was black. So I bought a bleeder kit and I'm going to do it myself every 60k or so. A pint of fluid is cheaper than a m/c, abs pump or new calipers.

 

[rangerj]

Scott,
If your master cylinder is original you may want to watch for any loss of the new found pedal firmness, or pedal "fade".

"YOU" make the point perfectly, that is, a car can be driven well out to the edge of its envelope and hold up if it is maintained, as in your case almost 300,000 miles (and counting). Conversely, a car can be driven poorly, beat on, and not maintained, and will be a troublesome pile of junk in no time.

Keep on raising the "bar" SDPatt. You give us a standard worth striving for.
rangerj

 

[bittertech]

I think I'm still running original (I'll have to ask my dad -- we've had 3 SHO's in the family, passed around, sold) fluid in my 90, and 249,673 on the odometer right now. And I'll be starting a job in 2 weeks that'll have a 108 mile round-trip commute (though we did swap my old SHO's engine with ~140k on it two years ago along with a 60k service).

Now if I could just figure out why I've lost 20hp according to my butt-dyno in the last 2 months..

 

[Shoaz]

BTW, it doesn't matter whether the original system was ever opened or not, it'll absorb water from the atmospheric humidity through the plastic reservoir.

Even in extremely dry Arizona I used to have to bleed my brakes every couple of track events (at a minimum) because most fluid wet bp is substantially lower than the dry BP. In a few weeks it would absorb enough water to become a problem. Now I have brake ducts and I use the $70/liter Castrol SRF and bleed them once a year, usually as a preventative measure. IMHO in this case for me the $70 stuff is actually cheaper since I seldom bleed the brakes now.

If that fluid is really the original fluid it's been essentially water saturated for a long, long time with a correspondingly low BP. It still won't boil if the fluid never hits high temps, which it seldom does during street use. It might accelerate wear on the hard brake lines, though (this is why many of the show car guys use DOT5, it doesn't absorb water at all, but is unusable for ABS cars).

Anyway, good to see you got it changed successfully. Don't forget to go cycle the ABS a few times and do it again. Otherwise there'll still be some old stuff in there.