I have a 1981 300 SD 126 Diesel 5 cylinder. The manual reccommends changing the brake fluid every Spring. Would synthetic brake fluid be ok to use, and would I NOT have to change it every year?

thanks

Nick

Do not use DOT-5 fluid in any street car. There is a DOT-5.1 that is compatible, however it won't increase your service interval. Every other year should be sufficient for that, or for DOT-4.

SYNpower dot 4 is what I use.


works just fine.

__________________
-1983 VW Rabbit LS Diesel (5speed, VNT/Giles build)

Ditto.....

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

I'm partial to Castrol LMA for DOT-4 applications.

Brake fluid change is a normal part of maintenance that should never be ignored on any car.

I will try the synthetic dot 4 fluid and change every 2 years, thanks for the input!

NIck

Isn't all brake fluid synthetic?

In the cars I have owned Dot 4 made a difference over Dot 3 as far as firmness of the pedal. Using dot 5 made no improvement over Dot 4 and it isn't required as my brakes don't get hot enough to merit using it.

I see no reason to use synthetic brake fluid other than boasting rights and lightening your wallet.

__________________
green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

You should absolutely never substitute DOT-5 for DOT-4 or DOT-3. DOT-5 is incompatible, and requires that all rubber parts be renewed when changing between that or the other two. I hope you mean DOT-5.1.

Many motorcycles take DOT-5, but I have yet to see a street car that took it.

Do people here like using ATE brake fluid? That's what I use in my other car. It's DOT4 I believe. In the Benz I just use valvoline something-something brake fluid that says "exceeds dot4" on it...

__________________
'82 300TD
'77 6.9
'75 280S
'74 280
'87 Porsche 944 turbo

I use genuine ATE-German DOT4 fluid every 2 years in all our cars. Its not that expensive, and supports the homeland...so why not.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Who's homeland????

__________________
Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John

The car's homeland.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Ach, der himmel, der Fatherland. I have used the valvoline synthetic brake fluid in some other vehicles. Seems to work OK. I think DOT5 is silicon brake fluid. I have used it in one car that doesn't get driven much. I have heard problems with colder temps and silcon brake fluids. Still I haven't had any problems with it.
Tom

The true synthetic seems not to be hydroscopic in nature . We have a car locally that has been sitting for probably twenty five years in storage.. The brake system seems to be as good as the day it was installed. Dot 3 or 4 would probably have rusted internally to the point of uselesness by now. Actually you could almost gaurantee that as those early systems were partially open.
That said and as already mentioned the car has to be prepped properly for the silicone fluid use. This involves an absolute flushing combined with all new seals. Sometimes the silicone will even leak by those. This stuff is not for the average driver. It seems to work well with real antiques that sit around a lot though.