Need Quick Answer - Ford High Perfomance Dot 4 Brake Fluid

[Macker]

Boss 302 Supplement indicates you can add Ford DOT4 LV High Perf. brake fluid, referenced Super Duty Dot 4, and a spec.# (don't have it in front of me unfortunately). Dealer called me concerned that the Boss is Dot 3 from factory and info. on the stuff I want them to use says not to put in cars spec'd for Dot 3 or Super DOT 4.....yet the spec. noted in the supplement (under prep for racing) is exactly what is referenced on the bottles I supplied.

Anyone confirm?

 

[VoodooBoss]

I ran DOT4 in my Boss with no issues. If you're not tracking your car stick with DOT3.

 

[Macker]

Just doing a lapping day. Will be the 3rd one in 3 yrs....so figured I'd go with the DOT4 performance stuff....to be safe. Thanks for the quick reply! Given that the spec. in the 302 supplement (racing prep) matches the one on the bottle, think I'm safe having the dealer add it.

 

[Mad Hatter]

If you are going to track the car, I would go with Castrol SRF. Expensive but lasts much much longer the fluids like ATE blue. I go 10 events on average with the same liquid, with only minor bleeding once in while. Normal Hipro brake fluids (Like ATE) go down hill fast if they boil. Saves a lot of time and bother.

 

[k98dave]

No issues with Dot 4, Factory used 3 because its cheaper. If you are mainly street and occasional track days Motul or ATE will be fine and much cheaper than SRF which is $$ overkill for mainly street duty. I flush brakes once a year for just street duty and just before any serious track days.

Actually one of the least hydroscopic fluids for everyday street cars is Valvoline Syn Power. Use it in my DD and lasts quite well

 

[TMSBOSS]

As Dave mentions, the down side to Dot 4 fluids are cost and maintenance. Dot 4 absorbs water and needs to be changed more often than Dot 3.

Dot 3 and Dot 4 can be swapped easily. Dot 5, silicone based does not mix with Dot 3 or Dot 4.

 

[Macker]

As Dave mentions, the down side to Dot 4 fluids are cost and maintenance. Dot 4 absorbs water and needs to be changed more often than Dot 3.

Dot 3 and Dot 4 can be swapped easily. Dot 5, silicone based does not mix with Dot 3 or Dot 4.

DOT3 absorbs moisture as well (I think), but perhaps less so than DOT4?

 

[k98dave]

DOT3 absorbs moisture as well (I think), but perhaps less so than DOT4?

All brake fluids will absorb moisture which lowers the boiling point. However dot 4 will retain a higher boiling point than 3 with equal amounts of moisture present. So...street only.... 3 or 4 but flush once a year. Track days maybe one or two events on dot 3 max. maybe a little more on dot 4. Once again as they always say "Your mileage may vary"

 

[Mad Hatter]

Total agreement! But... if you do boil your regular brake fluid once on the track or from hard driving. Make sure you change or bleed it before going on your favorite canyon run!! I did not and got a shock I did not enjoy very much.

 

[TMSBOSS]

Dot 5 being a silicone base will not mix with water and makes a great fluid for seldom used cars assuming you don't get the brakes hot and you can clean out the dot3/4 fluids. Great in classic Vettes.

Yes, both Dot3 and Dot 4 absorb water. Dot 4 at a much greater rate which then requires more frequent maintenance.

 

[blacksheep-1]

Cheap. works, doesn't boil..

http://www.frsport.com/Super-600-Racing-Brake-Fluid-_p_281550.html?gclid=CLyw9o_Y0M0CFYsehgodrqwG-g

 

[Macker]

Thanks for all the input guys. Have the new Ford DOT4 HiPo fluid in her now and ready to do some laps around Mosport. Actually captured the process on my dashcam. Tech did a good job. And after putting the wheels back on, took it out for a drive (respectfully....he new the dashcam was on), and then went out and re-torque'd the lug nuts.

 

[SDS]

FYI- The Motocraft DOT 4 in the Boss Suppliment has been superceded by Ford Motocraft PM-21 which is a DOT 5.1 and is not silicone based and mixes with DOT 4.

Steve

 

[Macker]

FYI- The Motocraft DOT 4 in the Boss Suppliment has been superceded by Ford Motocraft PM-21 which is a DOT 5.1 and is not silicone based and mixes with DOT 4.

Steve

Interesting. Part number on my invoice is PM-20. Guess you would have to ask for PM-21 specifically, otherwise, they just default to giving you the Hi-Po DOT4 I guess until they run out?

 

[k98dave]

Cheap. works, doesn't boil..

http://www.frsport.com/Super-600-Racing-Brake-Fluid-_p_281550.html?gclid=CLyw9o_Y0M0CFYsehgodrqwG-g

Good stuff,..... but you have to completely purge the old fluid first. AP recommends flush 100% with super 600, then purge and refill with fresh. So basically use twice the amount so not really that cheap.

 

[blacksheep-1]

Good stuff,..... but you have to completely purge the old fluid first. AP recommends flush 100% with super 600, then purge and refill with fresh. So basically use twice the amount so not really that cheap.

only the first time you use it, we've been running the stuff for 6 years in IMSA PWC SCCA without a brake related failure of any kind. besides, if you were switching over, why wouldn't you want all of the old stuff out?

 

[k98dave]

only the first time you use it, we've been running the stuff for 6 years in IMSA PWC SCCA without a brake related failure of any kind. besides, if you were switching over, why wouldn't you want all of the old stuff out?

The way it reads AP suggested flushing out old fluid (even is its was AP to start with) with new AP then flush again with more AP. I used to run ATE and would switch out between the blue (no longer avail) and the gold so it was easy to see when all the old stuff was out of the system.