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Brake fluid change?

2K views 29 replies 10 participants last post by  Reverb 
#1 ·
I fancy changing the brake fluid on the V6 as I don't actually know if/when it has been done before.

What I want to know is, how do I flush out the system properly. I'm fine with pad/disc changes but I've never changed the fluid before...?

Also somebody mentioned it would be a good idea to use Dot 5.1 fluid? Is that not standard?

Many Thanks :)
 
#2 ·
i use dot 5.1 fluid & mines a diesel , just seems to work better , when i changed mine i took the reservoir off the top of the master cylinder & emptied it & cleaned it out with a cloth .
then refitted the reservoir & filled with 5.1 then bled it all through again until the nice clean frsh stuff came through.
 
#4 ·
Dot 5.1 is the latest spec brake fluid Trav, synthetic iirc. It will not absorb moisture so brake pipes will not corrode from the inside out. It also has superior performance over lower Dot spec mineral fluids in terms of resistance to boiling and service life. It's good stuff!

Depending on how old your existing fluid is, you may see a subtle change in the colour of the fluid from the bleed nipples as the new fluid reaches each brake cylinder. I strongly recommend using a one-man pressure bleeding kit, but I prefer to top up the master cylinder myself rather than via the reservoir bottle in the kit (talking about the Gunsons kit here).

Your biggest worry should be to avoid shearing the bleed nipples when trying to first crack them open. A little trick I learnt when working on Cessnas, Pipers etc was that if a threaded fastener eg screw would not readily start unscrewing, "crack the seal" by gently trying to tighten it a bit more, then go for undo. It's saved me a few broken bleed screws in the past.

DO IT!!!:D
 
#6 ·
This is something I have been meaning to do for some time now!

I should get a bleed kit as I have 2 cars to do.

The Dot 5.1 is a lot more expensive than the Dot 4 - is it that much better for ordinary driving?
 
#10 ·
Anyone ever use the blue thunder 5.1 in a cav?

I ran it in my ibiza with my golf rallye brakes and it was awesome. Also if swapping the fluid out it makes it so much easier to do as the fresh stuff is blue and you know its made it all the way round. Then when you do the next swap go to the normal color fluid and bingo same theory!! :)

Also worth noting is make sure its 5.1 and not 5 as 5 will cause issues as the fluid will "congele" and not push through over the older stuff.
 
#12 ·
Its not the cheapest fluid in the world. I pick it up for around £10 a litre. I have seen it up as much as £18 p/l :scare: Shop about and you can probably get it down a little buy more than 1L helps too. With something like brakes there is no piont scrimping on quality and price. For something that you dont do that often a little more paying can pay back big benifits.

It also is a race spec fluid compatible with DOT 3, 4 and 5.1 Fluids so good for the change.

Maybe get a group buy together somehow. I need to do my car and there are clearly a few others who do and who can hand on heart honestly say they know when they last checked it let alone changed it!! Think i may look into this if ok with admins anyone know who to speak to re this?
 
#13 ·
Dot 5.1 is the latest spec brake fluid Trav, synthetic iirc. It will not absorb moisture so brake pipes will not corrode from the inside out. It also has superior performance over lower Dot spec mineral fluids in terms of resistance to boiling and service life. It's good stuff!

Depending on how old your existing fluid is, you may see a subtle change in the colour of the fluid from the bleed nipples as the new fluid reaches each brake cylinder. I strongly recommend using a one-man pressure bleeding kit, but I prefer to top up the master cylinder myself rather than via the reservoir bottle in the kit (talking about the Gunsons kit here).

Your biggest worry should be to avoid shearing the bleed nipples when trying to first crack them open. A little trick I learnt when working on Cessnas, Pipers etc was that if a threaded fastener eg screw would not readily start unscrewing, "crack the seal" by gently trying to tighten it a bit more, then go for undo. It's saved me a few broken bleed screws in the past.

DO IT!!!:D
Another top tip is to lightly tap the end of the bleed nipple with a small hammer a couple of times.
Just changed pads and fluid on my Omega and It's a different car now! Huge improvement.:Cool2:
 
#14 ·
#17 ·
Well I sprayed some PlusGas on the nipples this evening with the intention of changing the brake fluid tomorrow.

Which order should I undo the nipples? As I have never done this before I am not sure of the rotation :rolleyes:
 
#18 ·
do it in the same order as a brake bleed, starting from the furthest away from the master cylinder.

and the tip regarding removing bleed nipples by gently trying to tighten them 1st - top dollar its worked for me numberous times.

Rich
 
#23 ·
I have 1 litre of DOT 5.1 - the sun did come out but I was in the middle of tidying out the shed so I didn't get around to finding the capacity of the fluid system!

Hope I have enough - don't fancy having to buy a second!
 
#26 ·
Oh, and make sure you've only got about 15psi in the tyre you're using for pressure - any more than 20 and it goes t1ts up.
I have a couple of spares I can use - what is 15psi in real terms? about 1bar?
 
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