i had the wilwood BBK installed about a yr ago and the shop used DOT 5 Silicon brake fluid, the fluid is now a lil low and i have to pump my brake pedal to stop the car. i was goin to have the system flushed and go back to the standard DOT 4 brake fluid (non silicon)... not sure if i have to continue using the silicon fluid since it's now in the system??? or can i go back???

 

Oh, man, why did they do that?
You're stuck with Silicon brake fluid now unless you completely
flush the system, including the ABS system and the fluid that
likes to hide in the recesses of the calipers.

 

The shop that installed the BBK automatically went ahead and put the DOT 5 silicon fluid in, i wasn't aware untill he told me once the job was done. But my bigger prob. is that i see fluid leak around the front calipers...

 

WOW.....I can't believe they put in DOT5. I bet they didn't completely flush out the ABS system or the clutch.

I would get the car to a shop that can completely flush the system, would probably need to be a BMW shop. They would need to be able to cycle the ABS and clutch system for a complete flush.

Did they put on new brake lines? This may be the source of the leak. Definitely get it to a shop ASAP !

 

I'd echo much of this IF that's really what they put in it. Get a label or brand and find out. DOT 5 and DOT5.1 are not the same. They (hopefully) only referred to it as 5 and in fact put in some higher bp fluid than needed.

If not and it's silicone based you're in for some good flushing to remove it all. The problem with silicone based fluids are they are compressable. The pedal will not be firm even under hard braking. I've tried it, and it didn't work.

As for leaks that should have nothing to do with the type of fluid. UNLESS you have had silicon fluid in there for some time now and find the need to really push very, very hard on the pedal to stop the car. In this case the caliper may have experienced extreme pressures and be damaged. Hoping that's not the case I'd inspect the npt fitting into the body, the hose ends of course and the bleeder nipples and brass fittings on top and bottom. If there is signs of leakage at the body half or from a piston area they may be repairable also.

Part of that may also be a very worn down pad thus allowing one or more piston to become crooked in the bores (bad, change pads sooner! or put in shims) and you may find that this can be fixed by pad replacements.

Need more info before we all panic.