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Brake Fluid: Synthetic vs. Regular

1863 Views 9 Replies 7 Participants Last post by  CRJeepin
I have alwasy heard that you should not use Synthetic Brake Fluid, due to the hydrophylic vs hydrophobic properties. However, I have seen many on this forum are using Synthetic brake fluid.

Let's discuss which one is better to use. I plan on switching out my fluid every year.
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Re: Brak Fluid: Synthetic vs. Regular

Switch every year? How many miles do you rack up? :pBR:

I've had cars for like a decade or more with the original brake fluid and no troubles (of course I am not recommending people leave the fluid there for 10 years). I usually just do the flluid when a caliper or brake line goes bad which tends to happen at some point before the fluid really needs changing ... maybe every 3 or so years (I do check the fluid regularly though).
Re: Brak Fluid: Synthetic vs. Regular

A bottle of fluid is only a few bucks. I figure it's so easy to change why not do it when I do the axles, transfer, tranny...etc.
Re: Brak Fluid: Synthetic vs. Regular

Yearly change out is good. Despite popular belief, you can't tell the condition by the color. With regular heating/cooling cycles at the calipers with the rotors, lots of heat is built up that can pull or condense moisture from anywhere. Whether you know it or not or how long it takes to occur can vary. Brake fluid is one of the things that folks don't change often enough I don't think. They use their rigs all the time and don't realize there's a problem till it's too late, then you're replacing more stuff just to fix what broke. Preventative maintenance is a good thing on many levels.

I did a lot of searching for fluids back when I did the original Vanco 15" test kit. Blaine recommended I look for something with the highest wet and dry boiling points I could find. After some searching, he then told me what to look for. That stuff was great, but is no longer available. Having just upgraded my Vanco kit again, I went on the search again for new fluid for yet another change out. I do this yearly basically but forgot and ran a bit long on the last one. Fluids have changed a bit but what I use currently and have for a couple changes now is the Valvoline Synthetic Syn Power or whatever it's called in the grey/silver bottle with blue label. From what I can find here, it is slightly different than the really good old valvoline but still had the highest wet/dry boiling points. It works well and I've had zero issues. Just be sure to bleed properly. Been running this or the original good stuff since the original swap when the rig was basically new off the lot back in '05. Multiple change outs but like I said, went a little long on the last one.

Best of Luck,

Mike
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Re: Brak Fluid: Synthetic vs. Regular

When you change out, do you just do a mega-bleed and keep topping off the MC?

I've never changed mine out completely, but usually replace most of what's in the MC every other oil change, by pulling it out with a turkey baster and putting new in. Always do the same for the PS pump at the same time.

Was thinking I might do a more complete/thorough fluid change next time and don't have any better idea than sucking it out the bleeders at each caliper until I can see new fluid coming out. Wondering how you guys do it?

- DAA
I use the same as Mike, Valvoline synthetic. No problems!

When I change the fluid I take a turkey Baster and suck out all of the old fluid in the resivoir I can. Then at the farthest wheel from the master cylinder (passenger rear) I start bleeding till I get nothing. Then I fill the master cylinder with the fresh fluid and bleed the passenger rear till no bubbles show in the clear tube I have attached to the bleeder screw and that goes into a jar. I then move on to the driver rear and bleed till the fluid changes color and appears fresh. Then I do the same for the passenger front and then the driver front. The main thing during all this is to ensure that once you put fresh new fluid in the master cylinder, you keep it full of fresh fluid and don't let it run dry.
Sweetpee sums it up echoing Mike.

I like not hunting for a helper so I use



from http://www.speedbleeder.com/.
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f9k9 said:
Sweetpee sums it up echoing Mike.

I like not hunting for a helper so I use



from http://www.speedbleeder.com/.
Yea i have speedbleeders on mine also. Some people don't trust them and won't use them. I really like them and have had no problems with using them. Come to think of it, I think mine are made by Russell which is a division of Edelbrock.
Something I forgot to add... Regardless of with type of brake fluid you choose to use, DO NOT get it on any painted surface that you care about or don't want damaged. It will EAT PAINT! If it gets on a painted surface, it needs to be thoroughly removed/cleaned.

Also FWIW, and some one correct me if I'm wrong cause I am really not sure. But I thought either type was hydrophobic?
I've been told and read several places, including in a factory FSM (may not have been Jeep - could have been for another vehicle) -- that if you switch from standard to synthetic it's critical you do a complete system flush, to avoid serious safety risks of mixing the two types.

Personally I don't see the reason to do that -- I also run speed bleeders and do a thorough flush once a year; the seals on jeep brake caliper pistons seem to let a lot of crud get in because the first couple pumps from each caliper is always dark. Usually can tell a good improvement before and after the flush.

CR
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