i have BRAND new Wilwood brake calipers on my 32 hot rod. I am running dot 5 in an entirely new stainless brake system... with no leaks except what looks like the caliper pistons! I just put these on last night and next day I see a couple spots and caliper is wet at bottom. The bleeders and banjo are dry. Contemplating running alcohol thru and going to dot 4. I’m just disappointed as my system has no leaks other than this.. I’m beside myself... any suggestions??
Every production line will eventually have a defect. While rare, they do happen. Call them on Monday, and talk to a support person. They have always come through for me.
I'm gonna be bold and brutal and say read and comply with the 'king instructions! Pretty sure Wilwood specify dot 3 in all their products. I use dot 4, but dot 5 is a whole different kettle of fish! I might go and verify my suggestion later - I have some calipers new in the boxes somewhere. Chris
DOT 5 is synthetic. DOT 3, 4 and 5.1 are mineral. Your system will be built for one or the other, they are not interchangeable. Synthetic can eat normal rubber seals and hoses. You need to know what yours are.
A number of the companies that supply Corvette stainless calipers specify DOT 4 only AND that if DOT5 is used you can expect a leak and there is no warranty. Merry Xmas!
Brake fluid is generally "synthetic". DOT 3, 4 and 5:1 are glycol based, NOT mineral. DOT 5 is silicone based. There are mineral (petroleum) based brake fluids, but not 3, 4, 5:1 or 5.
I do like Wilwood but I have had a few leaks. They are not hard to split the calipers apart and check out to find the problem. I try to always keep a seal kit around.
That should have been step number one before posting here. If you have a problem with any product the first step should be contacting the company that made it and not posting on the net for a solution. I'd agree with Gimpy in that no matter how high the maker's rep for quality is, there is always that one item that slips by somewhere along the line. Bad O ring or O ring that got a tad off from the groove and got missed or ? Somewhere in their info or on their webpage there should be their suggested brake fluid. Wildwood does sell a dot 5 fluid in their line along with two grades of racing fluid that are on the line of dot 4 http://www.wilwood.com/BrakeFluid/BrakeFluid.aspx As far as Dot 5 vs 3 or 4 it came out just about the time I was pretty well done with working at front end and brake work when Dot 5 showed up for use on Fieros and Corvettes because it wasn't supposed to eat the plastic the Fieros were made of nor the paint on the Corvettes. It became the hot lick brake fluid for street rod builders soon after because of the not eating paint thing. The other selling point is that it is said not to absorb moisture as Dot 3 will. The NAPA Echlin brake rep told us in the early 80's not to buy the 5 gallon cans of brake fluid they sold if we didn't go though it in the shop fast enough. Meaning if the can sat around too long there was too much of a chance that it would absorb moisture. For that reason I don't even buy gallon cans of brake fluid any more even though I keep up with the brakes on about 8 rigs. My daily calls for Dot 4 but I have never had a rig that called for Dot 5 at this point.
Whether it has DOT Three, four, or five in it makes no difference on whether it would leak. If a new caliper leaks, there's something wrong with it. For years, Wilwood said not to put dot 5 in their calipers. I did anyway, and it's been in there for 15 years. Now they say it's okay to use dot 5, they even sell their own line of dot 5. I'm sure that switching brake fluid to attempt to solve your leak will be a waste of time. All dot brake fluid is 100% compatible with all brake seals and vice-versa. That is law. Switching fluid and ending up with swelled or broken down seals is the result of petroleum contamination in your brake system. One common source of this is cleaning brake parts with carb cleaner, mineral spirits or gasoline instead of brake cleaner. Just a tiny bit of petroleum in your brake fluid can break down the seals.
The use of modern seal compounds are normally compatible with both DOT glycol and silicone brake fluids, but they CANNOT be mixed. Using DOT glycol 4 or 5:1 in older DOT 3 vintage systems is also not recommended because of the chemical compound differences in older and modern seals. The best and safest fluid to use is what the master cylinder, caliper and wheel cylinder manufacturer/re-builder recommends.
You are undoubtedly correct, but my point was they are different and not interchangeable. What they are made of is irrelevant to the average guy, but being dangerous to mix them is not.
I disgree on the part about not using DOT in older systems. I've had dot 5 in my old system since 1981 with zero problems. I do admit that when the fluid was 30 years old, I flushed and bleed it. (Because a steel line was rubbing on the axle housing and wore through) I do agree that mixing other fluids with dot 5 is an issue, but only because you lose the benefits of using the dot 5. The mixture still works and will stop the car and will not ruin the braking system.
well, just wanted to put out there I flushed the lines with denatured alcohol and cleaned out each of the calipers by removing the pistons and wiping out the seals as well. Put some DOT4 in the system and bled, and now no leaks. I know all DOT5 should be the same, but maybe this was not? Don't know.. other than I have no leaks at the caliper pistons now. btw - if not mentioned this was a brand new SS brake system.