Brake fluid - dot 4 questions .

[optimusprime]

Just about to do a brake flush on my W124.
I see that i need type - Dot 4 and i have see a Dot 4 synthetic .Now i dont want synthetic Dot 4 .Also i see nothing to say on the containers if its one or the other, how do you tell .I think its a very bad idea to lable them both as dot4 when the one is synthetic and nothing like none synthetic, and it wont mix . Can anyone tell me a good brake fluid to purchase that will fill my needs ? a none synthetic one Dot4 .

 

[Codger49]

I now use MB brake fluid from the dealer. Its not that expensive and saves all the deliberation on which spec is best.

PS and BMW fluid for the BM.

 

[optimusprime]

Yes i know your right . I see 2 containers for the price of one on ebay mercedes original Dot4 fluid . But i dont see on the listing if its synthetic or not.Waiting for a reply from the seller .

 

[PobodY]

Why not go to DOT 5.1 as it's backwardly compatible?

It's DOT 5 that you want to avoid unless you've got a silicone-based (rather than glycol) braking system.

 

[190]

Don't worry about the DOT 4 being synthetic. All brake fluid is synthetic and the fact that it's only relatively recently been labelled synthetic is just marketing. I buy a good brand DOT 4 like Ate. No need to use MB fluid.

DOT 5.1 is compatible and has a better initial performance but it also absorbs water faster than DOT 4 so it wouldn't be my choice.


At the risk of more confusion you may also see DOT 4 +

Dot 4 + sometimes call Dot 4 LV, Dot 4 super, DOT 4 plus and there are probably others. They are all thinner fluids with a maximum viscosity of 750 cSt @ -40 Deg C. compared with 1800 cSt @ -40 Deg C for normal Dot 4. They are intended for use in brake systems with ABS etc to speed up performance in cold weather.
The reason for the various names is that there isn't yet an official Dot standard for low viscosity Dot 4 brake fluid so they are all just marketing terms. It’s very confusing that each manufacture thought it appropriate to invent their own name. Often you’ll see them marketed as DOT 4 + class 6 (or any of the other variations) which is a clue to what they really should be called. This refers to the European ISO standard 4925 class 6 which specifies the 750 cSt @ -40 Deg C.
Combining the North American standard DOT 4 with the ISO standard class 6 is a bit of a mess but I suppose the manufactures thought that if they labelled their containers with ISO standard 4925 class 6 they wouldn’t sell any.

 

[Codger49]

Don't think it actually matters as MB have only 1 recommendation for all cars - MB 331.0 Bremmsflussigkeit A 000 989 08 07.

MB 330.1 - General brake fluid - Mercedes-Benz Specifications for Operating Fluids
MB 331.0 - Brake fluids (DOT 4 plus, Specification 331.0) - Mercedes-Benz Specifications for Operating Fluids

PS Think its a synthetic - made from polyhydric alcohols. Bevolisten sheet 330.1 describes MB's Dot4 + as Dot 4 with a higher wet boiling point.

PPS Also states use of MB fluid is mandatory for warranty claims.

 

[optimusprime]

Just about to order this one . - picture ure. I did not know it was all synthetic.

 

[optimusprime]

Also if you, or anyone needs this , this is the ebay item listing number 302231406723 2x1 litre containers for £19.99 just ordered 2 containers . Thank you one and all for your help .

 

[Codger49]

By the way, the manufacturing date is usually incised or printed on the rear side of the container underneath the label.

The one in my garage that has the same 13 part number suffix and label print date of 10/14 is stamped 07/17, just in case anyone thought the suffix was a manufacturing year indicator.

 

[optimusprime]

Codger 49 can i find a date on the container some place ? . I would think if sealed from new no condensation can get in to the fluid . Plus the brake fluid in my car is 29 years old ,so it will be better than that .I dont know if it was ever changed before i was given the car .

 

[Codger49]

This is a reduced size picture of the brake fluid container in my garage, the impressed date 02/17 can be just about seen at the centre bottom.

 

[optimusprime]

I can see the date on the base of the container. So if and when it turns up i will check it out . Thanks fot that .

 

[optimusprime]

Coger49 Container stamp reads 06/20 05/20 so i am good to go . The mark was so faint i had to check it with a m/ glass . Fluid was delivered yesterday . Its a good deal for 2 containers genuin mb fluid . But i have the rear bumper off right now to clean off all the dirt, and waxoil the rear end . So next job in hand is the brake fluid flush .

 

[optimusprime]

Would like to know if any other member purchased a container or more from ebay seller ? .