Corvette Forum Editor

Great topic for today's how-to spotlight...
https://www.corvetteforum.com/how-to...e-fluid-368088

djnice

I used the Motiv Power Bleeder/ MVP-1118 adaptor. It leaked fluid if I went over 6 psi. Anyone have that happen? I tried the thicker pad and it did not help.

Jedi-Jurist

Mine leaked as well. I'm having no luck with it.

BEZ06

I only use the Motive as a pressure source!!

I DO NOT put any fluid at all in the jug. Any fluid remaining in the jug after you finish bleeding (and that can be a pretty substantial amount of fluid) is junk. You can't put it back into the bottle you poured it from - it's toast, and just needs to be thrown away.

So...try just using your Motive as a pressure source and I bet you won't have any problem at all!!

Just make sure you fill up the master cylinder after you bleed each caliper - you definitely don't want to run the m/c dry and push air into the brake lines!!!

BTW - I only need 6 to 8 psi to get a good bleed.

Below you can see my empty Motive providing pressure for bleeding/flushing the system on my old C6 Z06, but it works perfectly on my C7 Z06 as well:



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08G8V8

I've only used my Motive bleeder on my GMC Sierra and used it as a pressure source only, and it did a great job. I have the same metal 1118 cap and the plastic cap, but am not sure of the part number, but I figured the metal cap would be the best choice to ensure a good seal.....interesting to see these reports of leaking.

Not sure what this picture is from, as I've only owned a C7 Z51 and Z06, but the reservoir in this pic is much deeper than the reservoir on the C7. I will be doing my track prep here for my first event at the end of Sept, but the reservoir of the C7 looks very shallow.

BEZ06

As I mentioned, that picture is using the Motive on "my old C6 Z06".

Yes, the C7 m/c is almost square and looks like it's a little flatter, but I think it holds just as much fluid as the C6 m/c does:




I've done a couple of flushes of SRF into the system, and several bleeds on my C7 Z06 over the 17 months I've owned it, and it's no problem at all to perform using the Motive as simply a pressure source. Just make sure you keep the m/c full during the process.

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djnice

That makes sense using the Motive as a pressure source only. Thanks for the info.

Matthew McCarthy

Thanks to Theta for posting these and to BEZ06, bought the Motiv and only used as a pressure source at 8-10psi and it was flawless to flush the whole system from Motul 600 to Castrol SRF. I have never bled any brakes before and I am not a mechanic at all. Look forward to getting it back out on the track-'15 Base w/Z51 Calipers, DBA rotors and Carbotech XP8's ALL around.

USCG

2016 Stingray A8 TPW Aug'15: Doing a Dot-3 to Dot-4 changeover and would like to know how much Brake Fluid I'll need. Assume that the traditional 2-person pedal method should flush both the ABS & calipers?

When using the Dot-4, is it generally recommended that there be a complete flush every 12 months because of moisture-buildup?

BEZ06

1. You might get away with 1 quart/1 Liter, but I'd recommend to have at least 1-1/2 quarts/Liters on hand. If you're flushing in Castrol SRF it only comes in 1 Liter bottles, so get 2 bottles.

2. You can't bleed the ABS unless you have a GM computer to cycle the ABS valves in order to get fresh fluid into the ABS circuits.

The only way I know of to sorta bleed the ABS is to flush fresh fluid into the system, go out to an area with a surface where you can brake hard to get the ABS to activate several times to get some of that fresh fluid into the ABS circuits, then go back and reflush the system again to get rid of the old ABS stuff that got into the main system when ABS activated.

3. I guess you're flushing in DOT 4 for the track - is that correct?? DOT 3 will work fine for the street. All brake fluids (except DOT 5 silicon based fluid) are hygroscopic (water absorbing), which means they absorb moisture from the atmosphere under normal humidity levels. DOT 4 fluids will generally have higher dry and wet boiling points than DOT 3, but once the DOT 4 starts absorbing water they generally fall off more rapidly.

If you're running Castrol SRF you can get away with one good system flush each season, with probably some minor caliper bleeds after every couple track events. If you're running most anything else you should probably be doing a complete system flush after every several track events.

DOT 3 for street driving can last for several years. To my knowledge the C7 is the first Vette to have a recommendation in the Owner's Manual to flush in fresh brake fluid, and the C7 manual says to do it every 45,000 miles.

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USCG

Thanks! Good Info. Believe I'm going with Castrol SRF (at $65 liter).

Yes, the purpose is light track duty - maybe 3-4 annually. Is a pre-flush with a generic Dot-4 advisable? Is a complete flush necessary to get the new fluid thru the ABS system, or would several "partial" flushes, with ABS activation in between, be preferable since the ABS is up near the master cylinder? Obviously, the last flush needs to be complete to ensure 100% Dot-4 is at the calipers.

My experience with pads is that street pads have a terrific initial bite but fade fast, whereas race pads need to be warmed up first, but maintain good stopping when hot. Is there a good compromise pad, or is it best to just change-out the pads for track sessions? I don't care about dust - it's not a waxer!

BEZ06

I personally don't even worry about the ABS. You'll probably get into ABS sometime while on the track and that will get some fresh fluid into the ABS circuits, and I don't think the amount of DOT 3 coming out of the ABS will affect the overall system. On my new C7 I just flushed in DOT 4 and went to the track. I flushed in Castrol SRF about 14 months ago - didn't worry about ABS at all. I've run 17 track days so far with the initial flush of SRF, but I'll flush in fresh SRF before my next event after the first of the year and that will last all of 2018 with maybe a few very minor caliper bleeds after every couple events.

Pads - I don't think there's a good street/track pad. I think you need a good race pad for the track. I run my carbon ceramics on my C7, but on my old C6 Z06 I ran either Hawk DTC70/60 or later on Carbotech XP12/10. The C5 guys like the ST43 for the track, but I think even the base C7 is a little bit heavier so that a more aggressive pad is necessary. If I were running any iron brake C7 with stock calipers and rotors, I'd probably be running Carbotech XP20 front and XP10 in the rear, and swap back to the OE pads for the street - the pads are very easy to swap on the C7.

Just MHO, YMMV!!

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USCG

Again, Thanks for the good info. Saved me another day or two of confused reading! Was turned on to a website called "RaceOptimal.com" that shows the best line through various racetracks around the country.

Good Luck & Merry Christmas

badhabit_wb

I know this is an old thread but if I buy a Mongoose GM Pro do I have to get a quick subscription every time I use it?

Thanks

dbletap_ed

Been a while since anyone has asked a question on this thread and sure hope someone sees this.

I see many folks talking about pressurizing the system to blead the system. My question is has anyone blead the system using a vacuum pump? Either the nice air pressure driven ones or the hand pump. The good old pump the peddle method works but a vacuum pump is a one man operation.

badhabit_wb

The vacuum pump works but the motive pressure pump works better. I've used both but when my last vacuum pump broke I bought the motive. Should have bought it years ago.

djnice

I use the Motive pressure tank with air only. I can't get frim brakes without using the pump pedal method to finish the job.

dbletap_ed

Question, did you start with a system with air in it? I can understand if had system open but just flushing why would you introduce air?

badhabit_wb

Most of us fill the master cyl full of fluid and don't put fluid in the motive container. You just have to be careful not to empty the mc or you will introduce air.

JMII

been doing it this way for years. All my track buddies use the same method whether its on a Miata, BMW, VW or Porsche.

It takes me 2.5 bottles @ 500ml each (Motul 660). Depending on pad thickness and wear the last 0.5 of a bottle might be needed to top off.