6.0L Power Stroke Engine and DrivetrainDiscussion of the 6.0L Power Stroke diesel engine and drivetrain in the 2003-Up Super-Duties and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 6.0L Power Stroke engine.
I'm about to completely flush and change my brake fluid on my '05. Ford specifies DOT 3 in my owners manual and I've been pretty strict about using factory specified fluids everywhere in the truck so far. My question is this: is there any harm in using higher grade fluid like DOT 4 or 5?
I'm a little surprised that they don't specify at least DOT 4 in this day and age for a truck that is rated to tow 6 or 7 ton trailers down long mountain grades, I would think that a higher boiling point is always a good thing. In my old 7.3, I ran ATE Super Blue racing fluid that I had for a track car, it has the highest boiling point of any fluid. Overkill maybe, but it's always nice to have a large buffer.
Sorry for the long post, but is there any reason not to use this? Why does Ford only use DOT 3? TIA.
Off the top of my head I can't think of one US based manufacturer that uses anything but DOT 3 (other then maybe Corvettes). Most European based manufacturers from my recollection use DOT 4, due to their potential higher energy dissipation and use of higher metallic pad compounds that would allow for a higher degree of heat transfer to the calipers.
Keep in mind that DOT 4 tends to absorb moisture at a higher rate then DOT 3, and that after about 3 years both fluids end up with similar boiling points if they are not changed out.
And that's the key. SAE studies have shown that the American public does not follow brake fluid maintenance. And based on this fact and that after three years both fluids will be at the same point, in general it does not matter.
Therefore in the OE automotive industry the manufacturers then base their fluid boil tests around this lower point, typically running fluid boil testing at Townes Pass in Death Valley. Although some manufacturers also use other locations.
One of the characteristics of the OE brake pads used one the '99-04 chassis was that it utilized an underlayer (red in color) that acted as a heat barrier to assist in heat resistance. The front pads also used a stainless steel heat shield to protect the caliper boots. Later, the insulators on the back of the pads had two quarter moon projections to take place of the SS shim. Also if you look at the rear calipers you will see heat fins similar to an air cooled engine to assist in brake fluid cooling.
While our brakes in typical driving run rather cool, with aggressive (think Ambulance in cities), larger then stock tires, or mountain passes with trailer brakes not doing their share, the brakes can get over whelmed as these brakes do not have a lot of reserve.
But to your point, IMO YES, "for a truck that is rated to tow 6 or 7 ton trailers down long mountain grades, I would think that a higher boiling point is always a good thing".
__________________
Jack
Former Vehicle Test Manager - Friction Products
Thank you, FMTRVT. I agree that most Americans never have their brake fluid changed but I blame manufacturers for not including it as a maintenance procedure. I've never seen it listed in a schedule for any domestic vehicle I've owned. As you probably know, most European makers have specific/regular change intervals listed in the manual that comes w/ the car and it's part of the normal schedule if service is performed at the dealer. BMW is annual, if not mistaken, Porsche and MB are semi-annual, etc...
BMW's annual change is a little more than necessary, IMO, (and another revenue-enhancer for their dealer service network), but once every 2 or 3 years is very prudent. All brake fluid is hydroscopic and attracts dirt as well as moisture, there is nothing special about American brake systems to prevent this. According to the schedule printed w/ domestic vehicles, you never change the fluid. Ever.
It's one of the first things I do on any used vehicle I buy, as well as either change or clean-out the reservoir. (I boil them out w/ degreaser and rinse w/ distilled H2o, then dry in warm oven). I've bought otherwise well-maintained vehicles w/ 10 year-old fluid in the brake system that looks like dirty toilet water,all because no one ever told the owner that it needed to be changed!
How's your average driver going to know to do that if the book doesn't say so?? i know plenty of car guys in the U.S. who don't know about this. I blame the domestic auto-makers and it's something I've never understood. I'd think they'd specify it just to CYA from a liability standpoint if heaven forbid there was a terrible accident that could be blamed on brake fade/failure from filthy contaminated fluid.
That's because of another SAE study which showed how many people in the 70's and earlier were screwing up their brake system by putting in motor oil, trans fluid, hydraulic oil and even antifreeze. So now reservoirs are sized and sensored so when the dash light goes on the brakes need to be replaced and the mechanic can do the brake fluid thing.
There was even some discussion on how to seal the system so no one but a mechanic / dealer could possibly put fluid in the system. Even some transmissions are like that now.
There are times I wish that brakes were no so simple mechanically that a person who has done one or two now becomes experienced and can lead others to disaster.
__________________
Jack
Former Vehicle Test Manager - Friction Products
That's interesting but the euro manufacturers list it as a service procedure in the maintenance schedule that the dealer is supposed to do on scheduled services. Most all owners manuals these days have the big disclaimer about taking your vehicle to a qualified repair facility for certain procedures, so I still don't understand why it is not recommended to change brake fluid.
I'm of the camp that trusts very few people, including dealer techs, to do work as meticulously as I do it. I'm the best guy I know and when I do it, I know 100% that it was done right w/ no short cuts or dirt getting where it's not supposed to go.
1) First, I use a large turkey baster to suck all of the fluid out of the reservoir and into a container held right next to it. You want to be careful not to get brake fluid on any painted parts, I do this part completely under the hood. If you do spill any drips, dump some clean water on inner fender or where ever it drips. Water dissipates brake fluid.
2) Open one bleeder valve after another and GENTLY pump the pedal a little to clear most of the line. You could also just open the bleeder, put a piece of small hose on it and let gravity run its course but my way is quicker. You don't want to pump the heck out of the pedal or make it travel further than it usually does, this can destroy the seal in the master cylinder, especially on an older MC. (Ask how I know...).
2A) You can also hook a small vacuum pump to each bleeder and suck fluid out if you have one but a couple gentle pedal pumps works great and is quicker, IMO.
Now the system is fairly empty. It does not have to be completely empty at all, new fluid will pump the dirty stuff out fast when you get to the refill/bleed part.
3) This step is optional but if the old fluid has been in for years, the reservoir is usually really dirty. On some vehicles, you can buy a new brake fluid reservoir by itself, (w/o purchasing a master cylinder), if the old one is horrible and a new one is cheap, this would be a no-brainer. Usually they are either unavailable separately or expensive, however. It's always a judgement call. Sometimes the res is fairly clean. You can bet your ass that the dealer won't clean it out, they either replace it or simply pour new fluid right back in a dirty one. I've seen many w/ a real nice layer of sludge on the bottom, I won't have that in my system.
Soooo..., I usually clean the reservoir. They are always removable, most just pull straight up w/ a little persuasion. Our trucks have what looks like a pin or two clearly visible that needs to be removed in order to lift it off. (Haven't done this truck yet but I can see the pins).
Lift the reservoir off. Always have a small plastic drain pan next to MC and lift it right into that, it will always still have a little dirty fluid in it which will now drain freely out holes.
I rinse the reservoir out w/ real hot water, (usually boil a pan-full and then let it cool slightly), I also use soap and a clean small toilet brush or similar to scrub it out. Many reservoirs have chambers that you cannot get to w/ brush or fingers, you just have to pour soapy, hot water in and shake it a few times. I always figure that if I get 90% of the crap out on those I'm doing well. Plus you will definitely get anything remotely loose that will go straight into the new fluid.
Once you get it as clean as you can, rinse w/ distilled H2o or at least really clean water. If you have a bottle of Evian laying around, that'll work. I clean the screw-on cap and rubber seal at the same time as the res and rinse as well.
4) Very important step: You need to dry the reservoir 100% before re-installing. You can blow some compressed air through it if you want for starters but it's usually not that helpful. You need to let it sit upside down on a clean piece of paper in the Arizona sun or the like for an hour while you do the rest of your brake job or whatever you're doing. If you don't live in the desert, a warm oven works great. I turn my oven on low for a while, then turn it off and set the res inside upside down on a piece of newspaper. If the oven is too hot to stick your hand inside for a couple seconds, you over-did this part and you are probably going to burn your house down and melt your resevoir. If you're not long on common sense and mechanical ability, you should not be working on brake systems, period. Pay attention to the part about turning oven OFF before putting res inside.
I'm a painter so I have heat-guns, (like a hair blow-dryer but a lot hotter). They work great for drying out resevoirs as well. You need to make sure that there is zero moisture in the res before putting it back on. Can't stress this enough.
Once you have your cleaned reservoir, or bought a new one , simply re-install it. The MC, (which should have been covered with a clean, lint-free rag this whole time), will still have some wet fluid on the rubber grommets where the res attaches and they usually pop right back in easily. Fill it w/ clean fluid.
There are a couple of accepted ways to bleed brake systems, I'm going to assume that if you're messing with the hydraulic part of your brakes, you know how to do it. While bleeding, the new fluid will quickly push out the old and you will be able to clearly see the new fluid coming out the bleeders, assuming there are no blockages in the system. The bleeding procedure is where you discover whether your lines are clear by the pressure of fluid expelled from bleeders. If any of the four wheel positions does not bleed well, investigate at this time and remedy. This is when you discover that you need new rubber lines. They can look OK on the outside but be nearly swollen shut on the inside if they are old.
If the difference is not clear between brand new fluid and what was already in your system, you did not need to do this procedure in the first place.
It took me longer to type this than it takes me to clean a reservoir but as FMTRVT correctly pointed out, brakes are no joke. I wrote this like a lawyer, (which I'm not), so as to cross all "t"s and dot all "i"s. Hope it helps.
1) First, I use a large turkey baster to suck all of the fluid out of the reservoir and into a container held right next to it. You want to be careful not to get brake fluid on any painted parts, I do this part completely under the hood. If you do spill any drips, dump some clean water on inner fender or where ever it drips. Water dissipates brake fluid.
2) Open one bleeder valve after another and GENTLY pump the pedal a little to clear most of the line. You could also just open the bleeder, put a piece of small hose on it and let gravity run its course but my way is quicker. You don't want to pump the heck out of the pedal or make it travel further than it usually does, this can destroy the seal in the master cylinder, especially on an older MC. (Ask how I know...).
2A) You can also hook a small vacuum pump to each bleeder and suck fluid out if you have one but a couple gentle pedal pumps works great and is quicker, IMO.
Now the system is fairly empty. It does not have to be completely empty at all, new fluid will pump the dirty stuff out fast when you get to the refill/bleed part.
3) This step is optional but if the old fluid has been in for years, the reservoir is usually really dirty. On some vehicles, you can buy a new brake fluid reservoir by itself, (w/o purchasing a master cylinder), if the old one is horrible and a new one is cheap, this would be a no-brainer. Usually they are either unavailable separately or expensive, however. It's always a judgement call. Sometimes the res is fairly clean. You can bet your ass that the dealer won't clean it out, they either replace it or simply pour new fluid right back in a dirty one. I've seen many w/ a real nice layer of sludge on the bottom, I won't have that in my system.
Soooo..., I usually clean the reservoir. They are always removable, most just pull straight up w/ a little persuasion. Our trucks have what looks like a pin or two clearly visible that needs to be removed in order to lift it off. (Haven't done this truck yet but I can see the pins).
Lift the reservoir off. Always have a small plastic drain pan next to MC and lift it right into that, it will always still have a little dirty fluid in it which will now drain freely out holes.
I rinse the reservoir out w/ real hot water, (usually boil a pan-full and then let it cool slightly), I also use soap and a clean small toilet brush or similar to scrub it out. Many reservoirs have chambers that you cannot get to w/ brush or fingers, you just have to pour soapy, hot water in and shake it a few times. I always figure that if I get 90% of the crap out on those I'm doing well. Plus you will definitely get anything remotely loose that will go straight into the new fluid.
Once you get it as clean as you can, rinse w/ distilled H2o or at least really clean water. If you have a bottle of Evian laying around, that'll work. I clean the screw-on cap and rubber seal at the same time as the res and rinse as well.
4) Very important step: You need to dry the reservoir 100% before re-installing. You can blow some compressed air through it if you want for starters but it's usually not that helpful. You need to let it sit upside down on a clean piece of paper in the Arizona sun or the like for an hour while you do the rest of your brake job or whatever you're doing. If you don't live in the desert, a warm oven works great. I turn my oven on low for a while, then turn it off and set the res inside upside down on a piece of newspaper. If the oven is too hot to stick your hand inside for a couple seconds, you over-did this part and you are probably going to burn your house down and melt your resevoir. If you're not long on common sense and mechanical ability, you should not be working on brake systems, period. Pay attention to the part about turning oven OFF before putting res inside.
I'm a painter so I have heat-guns, (like a hair blow-dryer but a lot hotter). They work great for drying out resevoirs as well. You need to make sure that there is zero moisture in the res before putting it back on. Can't stress this enough.
Once you have your cleaned reservoir, or bought a new one , simply re-install it. The MC, (which should have been covered with a clean, lint-free rag this whole time), will still have some wet fluid on the rubber grommets where the res attaches and they usually pop right back in easily. Fill it w/ clean fluid.
There are a couple of accepted ways to bleed brake systems, I'm going to assume that if you're messing with the hydraulic part of your brakes, you know how to do it. While bleeding, the new fluid will quickly push out the old and you will be able to clearly see the new fluid coming out the bleeders, assuming there are no blockages in the system. The bleeding procedure is where you discover whether your lines are clear by the pressure of fluid expelled from bleeders. If any of the four wheel positions does not bleed well, investigate at this time and remedy. This is when you discover that you need new rubber lines. They can look OK on the outside but be nearly swollen shut on the inside if they are old.
If the difference is not clear between brand new fluid and what was already in your system, you did not need to do this procedure in the first place.
It took me longer to type this than it takes me to clean a reservoir but as FMTRVT correctly pointed out, brakes are no joke. I wrote this like a lawyer, (which I'm not), so as to cross all "t"s and dot all "i"s. Hope it helps.
Three items to add.
1. Once you start bleeding the system do not let the Master Cylinder go dry or you have introduced air in the system.
2. Start at the wheel furthest from the master cylinder and then work your way to the next furthest and so on.
3. Dot 3 and 4 are compatible with each other. Dot 5 is not and if dot 5 is used the entire system must be flushed first with an inert agent.
It's not as big a job as it sounds. I now use the synthetic prestone dot 3. Claims to attract less moisture. Harbor Freight has a vacum bleeding kit for 20 bucks that actually works quite well. about an hour job if the truck is on a lift.
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