Globalinx

Hi all, I recently Installed LS400 brakes on GS, and switched from DOT3 to DOT5 fluid. I went to a track event with new pads on all corners. For some reason my rear pads shaved to the bracket with in the first not hard driven 10 laps. (callipers not seized) Just wondering if the pads were bad or the LS callipers or the fluid change had something to do with that. And yes! The LS brakes stop fast continuously, but make sure get the good ones, as mine were giving me headaches for the first month and a half by leaking. 3 rebuilds later, and its all good now. BTW I was running DOT 3 at that time leaking problems.

porn-adkt

iTrader: (37)

Did you completely flush the system before switching DOTs?

First you never go from DOT3 to DOT 5. DOT 5 is a different fluid in itself and will react with DOT 3, our cars are not made for DOT 5, if not properly Done DOT 5 will destroy your seals with in a month or so. Your caliper will leak and you can kiss your BMC goodbye. The pedal will become spongy, you will not feel a difference in swapping over to a bigger caliper.

i would keep an eye out on any rubber seals. check the BMC cap to see if it starts to swell, if it does then your screwed..been there done that...Good luck..

Globalinx

I was persuaded by the shop to switch. It appeared that they have drained the whole system, including vacuum pumping all lines and draining all callipers. Would that be ok, or I am still screwed? What is BMC cap? Is it the one that is on top of the brake fluid container?

porn-adkt

iTrader: (37)

Not sure why they would recommend this. Dot 4 and 5 perform better than 3, thats no rocket science, blah, bla, bla.

But some cars are not suited for that DOT, and work just as well as DOT 5, i have DOT 5 in my supra but it has never seen anything but DOT 5. Wilwoods/lines and Master were all new and introduced to DOT 5.

I have DOT 3 on my GS4 will willwood BBKs all around. performance is top notch and as good as the supra. except for the specs for DOTs3 Vs 5, Ie. heat, moisture absorption, Blah, bla bla.

the only way i would go with DOT 5 on the GS is if my Master was brand new and never saw DOT 3, but a new master costs money.

My experience has been even a flush will still not get all the existing fluid out, its kinda of a coin toss, one that i would not take again.

If you use your car strictly for the track i would say, ok Maybe DOT 5 is the way to go, but then again why use LS4 calipers on stock rotors? i would do it right, BKK or partial BBk, maybe two piece rotor aluminum hats, or aluminum calipers, Blah, bla bla.. But thats just me.

The left is a OEM cap The right is a OEM cap after DOT 5 was introduced and system was flushed.

Globalinx

Cool, thanks for the info. I used LS4 callipers with LS4 rotors as they are 4 piston instead of 2. I can feel a difference in stopping power. What did you do to fix the problem you experienced and whats the cost? I assume switching back now again would make things only worse? Or its time to run back and put a regular DOT 5.1 non silicone fluid?

Measured

iTrader: (1)

I have been on Motul DOT 5.1 with no issues and no leaks for almost a year now.

Globalinx

5.1 is not the same as 5. One is synthetic another one is silicone based.

Measured

iTrader: (1)

I appreciate your input and I do understand the differences.

Globalinx

I guess what I meant, is that there is no reason fo DOT 5.1 to leak. What Im trying to figure out, is what to do with my DOT 5 in my system now. Is it too late I can switch it say to DOT 5.1?

Measured

iTrader: (1)

I figured as much, but I dislike making assumptions. ****-adkt, would be your best person for that sorta information. You'd really have to flush out the whole system and dry out the seals and hopefully not rebuild anything if it was that tough on the system.

Globalinx

So I bought Motul BRF600. We'll see how that goes.