# Type of brake fluid for MkIV? DOT3? DOT4?



## phatvw (Aug 29, 2001)

I used the search and I don't understand why this isn't in the FAQ so here goes...
What is the rating of the OEM brake fluid in MkIV Golf/Jetta/GTI cars? What is an inexpensive alternative to the OEM fluid that provides better dry/wet boiling point performance but is guaranteed not to corrode the OEM seals?


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## MikekiM (Aug 21, 2001)

VW's use DOT 4. Do NOT use DOT5.
Any DOT fluid will work just fine in our systems. If you're not racing you shouldn't need to worry. They all have higher boiling points that you'll encounter on the street.
If you're racing, look for a quality fluid like from Castrol or Motul.


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## phatvw (Aug 29, 2001)

*Re: (MikekiM)*


_Quote, originally posted by *MikekiM* »_VW's use DOT 4. Do NOT use DOT5.
Any DOT fluid will work just fine in our systems. If you're not racing you shouldn't need to worry. They all have higher boiling points that you'll encounter on the street.
If you're racing, look for a quality fluid like from Castrol or Motul.


Thanks for the quick reply. I will look for a quality DOT4 fluid then. Or maybe DOT5.1 since it uses very similar chemistry.
I just had my first track day and at the end of one of the 20 minute sessions, I experienced a ton of brake fade going from 120mph down to 30mph for a turn. I suspect that boiling fluid contributed to this, as did the less than optimal stock pads. I know I need to replace both if I want to do any more performance driving and I don't want to put the wrong stuff in there and kill my system


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## fat biker (Feb 16, 2001)

*Re: Type of brake fluid for MkIV? DOT3? DOT4? (phatvw)*

Do you have the owners manual?
Does the owners manual specify which grade of brake fluid?
Have you read the owners manual?
It amazes me how many questions get asked here that could easily be answered my opening the owners manual.
After busting your rump, I will now contribute something...
Either of these are excellent brake fluids, there are several high quality brake fluids available. It usually comes down to cost/benefit and availability.
Ate 200 - 536 dry/392 wet [$10/liter] www. raceshopper.com
Motul RBF 600 - 593 dry/420 wet [$25/liter] porterfield-brakes.com
HTH
fat biker


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## C_Diddy (Mar 30, 2011)

*MkIV Brake Fluid Discrepancy*

Fat Biker has acted like some of the questions regarding brake fluid could be solved if people just read their owner's manual. Normally he would be right, but not this time (at least not in my case), because my original VW manual calls for *DOT 3*, Standard 116, Spec J1703. _BUT_ when I went to pour this into my Golf's brake fluid reservoir, the filler cap calls for *DOT 4* brake fluid. :screwy: Since I was in a pinch (and not a little confused), I went ahead and poured in the DOT 3 stuff that the owner's manual called for. Any ideas if this tolerable or what the brake system _actually_ needs?

-C_Diddy


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## greyhare (Dec 24, 2003)

DOT3 will not hurt but, in your case I would use DOT4.

As a general guideline DOT4 in a DOT3 system is fine. DOT3 in a DOT4 system will not hurt but may have fade issues under heavy use.

DO NOT use DOT5 it is not compatible with the system.

FYI resurrecting a post from 2003 is frowned on; better to start a new one. You can reference the old thread if it is relevant.


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## Elwood (Aug 10, 2001)

greyhare said:


> DO NOT use DOT5 it is not compatible with the system.


As long as we are here...
DOT 5 is synthetic and wonderful in any brake system that DOESN'T have an ABS pump. The ABS pump churns the stuff into foam and renders your brakes useless. Great in many motorcycles though (doesn't eat paint, either).

DOT 5.1 is suitable and can be used.


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## Urbanfundamentalist (Aug 21, 2009)

The DOT numbers correspond with  minimum wet AND dry boiling points. The higher the DOT number, the higher the corresponding boiling points. So for a street driven car, DOT 4 is better than DOT 3, DOT 5.1 exceeds DOT 4, etc.

That said all brake fluid is not equal. DOT 5 is silicone based and non corrosive, generally used in historic/vintage cars so it won't corrode linings. From what I've heard the feel is very spongy and as someone pointed out might not work with ABS. Despite the strange moniker, DOT 5.1 is the next glycol based step up from DOT 4. 

For a street driven car, avoid racing fluids. Moisture is the enemy of brake fluids/lines and most street fluid is designed to resist moisture absorption since it will likely not be changed for 2 or more years. Racing fluid on the other hand is often designed with the knowledge that racers (the kind that regularly race on the track not between stop lights) will swap their fluid seasonly, if not between every race. Also, even though some may have insane dry boiling points (like 600+ degrees), they may still be rated at only a DOT 3 because their wet boiling point is less than half of that. Again a design consideration since that fluid, flushed properly, will never be in the car long enough to absorb much moisture.

If your car will see serious track time, use a race fluid and be aware of the need to change the fluid more frequently than a "street" fluid. If your car will never see track duty and you are unlikely to flush the fluid regularly stick with a DOT 4 or 5.1 fluid.


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## Tollis (Nov 13, 2010)

If you have ABS do NOT use DOT5 "racing" fluid it will cause brake failure. Just use a DOT4 fluid you can even get DOT4 Synthetic at Canadian Tire, Napa etc. Dont waste your money on fancy fluid for a street car. Remember your supposed to flush your brake system every year anyway why waste the money.


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## BsickPassat (May 10, 2010)

phatvw said:


> I used the search and I don't understand why this isn't in the FAQ so here goes...
> What is the rating of the OEM brake fluid in MkIV Golf/Jetta/GTI cars? What is an inexpensive alternative to the OEM fluid that provides better dry/wet boiling point performance but is guaranteed not to corrode the OEM seals?


DOT4.

Inexpensive brake fluid? ATE Type 200 & ATE super Blue (doesn't meet DOT spec due to the blue dye).

If you have ESP, then it requires a low-viscosity DOT4, such as ATE SL.6 (since ESP were introduced to MKIV's in 2003)


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