[suso]

Hi everybody,

When I bought my 94 Aero about a year ago I realised that the TCS light was on for a long time. At this forum I read that is this light was on for more than 5 seconds I could find that the brake fluid had to be replaced.

OK, I told my garage to test the fluid and they told me it was OK, no replacement needed. About a month ago I had to replace the ABS pump (electrical part) and the ABS pressure switch. That could drive my pocket broken if I had not found second handed parts at www.partsasap.com (Andy is a great guy). Once the parts were replaced the TCS light turns off in about 3-4 seconds.

These things had me think that it coukld be a relationship between the long lasting TCS light and the gone pressure switch. After asking some mechanics of confidence, I can tell you that if your TCS light is on for more than 5 seconds and you have your brake fluid with correct properties you should chek your pressure switch... if its worn your ABS pump has serious difficulties to reach the working pressure and works more time than needed and this could brake your pump.

I can tell you your pocket doesn´t want to suffer a broken ABS pump.

Greetings from Spain

 

[Mark B]

I am always a bit suspicious about testing brake fluid. Even if your garage has equipment to test the boiling point, they will almost certainly test the fluid in the reservoir. Unfortunately, it's the fluid in the calipers that gets hot when stopping the car, not the stuff in the reservoir, so it's the caliper fluid that should be tested. Anyone who has ever changed brake fluid knows that the fluid drained from the calipers tends to be dark whilst the fluid in the reservoir looks like new. Most of the water that is absorbed into the brake fluid actually comes through the flexible hoses near the caliper, rather than being absorbed into the reservoir from the air. It's strange, I know, but it's true.

I think the sensible approach has to be that unless you know for certain that the fluid was changed less than 2 years ago, change it regardless, and use DOT 5.1 fluid, or Super DOT 4 fluid, but NEVER the silicon based DOT 5 fluid. Change it at least every two years.

Happy new year.