MB-Dude

In preparation for changing the accumulators on a '96 SL600, I dutifully visited my MB Parts Counter and proceeded to order a bottle or two of Hydraulic Fluid (MB p/n 000.989.91.03.10) that I knew I would need for the change-out. The price, per bottle, sent me reeling... even with my discount.

Question: Does anyone know an acceptable alternative to the "real" Hydraulic Fluid (MB p/n 000.989.91.03.10)?

At a list price of over $17 per quart/liter, this can get a little outrageous. The stuff sort of has a texture and odor of brake fluid, but I hesitate to experiment with brake fluid in my hydraulic system (although they should be compatible).

TonyG230

I am doing the same on my C coupe and found MB fluid price to high ( $19.00 1/2 liter ) here in Canada. I did look at the container and notice the Dot 4 plus temperature rating and will buy from another source ( auto Parts Store ) Brake fluid is brake fluid if temps are same.

MB-Dude

Makes sense. I know the Hydraulic Fluid in my '96 SL600 gets quite hot, and believe this is normal as the fluid is continually passed through the pump. Also, use of the fluid in hydraulic shocks causes a lot of pressure, which equates to heat. I assume this is the case in virtually every MB model. I'd be interested in reading how it turns out. In the meantime, I continue to research the topic. With the price of about US$5 for a quart of DOT-4 Brake Fluid versus the US$17 for the OEM stuff, I'm seriously considering it.

Kestas

NO, NO, NO!!!! You cannot substitute brake fluid for regular hydraulic fluid. Hydraulic fluid is a mineral oil, brake fluid is an ethylene glycol. The two are not at all compatible and using brake fluid will ruin the expensive seals in short order.

The 000 989 91 03 10 fluid is the same used for my hydraulic top. A while back I queried the forum for a cheaper substitute fluid. No one could verify an acceptable alternative. I had my lubrication expert colleague reverse-engineer the fluid and all he could say is that the 000 989 91 03 10 fluid is a high-quality hydraulic oil. Considering how expensive the mistake may be using the wrong fluid, I just went with the MB-supplied fluid. I had to replace a hydraulic cylinder for the top which cost $125... and there are five more like that for the mechanism!

Use 000 989 91 03 10 fluid MB fluid. This is one place you don't want to make a mistake.

MB-Dude

Thanks Kestas for the information! Glad I haven't started the suspension work yet. Guess I'll take out a second mortgage for the MB fluid.

SteveUrban

Febi-Bilstien carrys the MB fluid. It is the exact fluid w/o the MB price. I paid about $9.00/qt.

Cheers,
Steve