how much brake fluid to do a full flush/change?

Hi all,

I have just replaced all of the seals and pistons in my brakes and am just about to order new motul rbf660 fluid. As the fluid is pretty expensive £20 half a litre or thereabouts I want to order enough for a full fluid change so none of the old stuff is in the system but also don't want to be pumping through new fluid and then wasting it. So how much do I need?

Rob

I have searched and can't find much info

I think I used just over a litre when I did mine. There is a sticky thread in technical I think with oil, coolant etc. recommendations. Can't link to it as I'm on the phone

Thanks a lot

I have bought 2 ltrs, there does seem to be some conflicting info regarding a full change/flush to a higher spec fluid, I've read on here to drain it all out and then refill/bleed with new. Others seem to say that just adding it to the master cylinder on 'top' of the old and keep bleeding through is the way to go.

I'll do some research but any advice from people that have changed fully to a higher spec is appreciated.

thanks

Rob

I just topped up the fluid and pulled it through until it ran clear. If you empty the system it can take ages to bleed properly, also if you have ABS it's a right pig!

I just topped up the fluid and pulled it through until it ran clear. If you empty the system it can take ages to bleed properly, also if you have ABS it's a right pig!

Thanks Budz, That was my thinking too but wanted someone else to confirm

I'm going to push the pistons in at the caliper so there is no room for old fluid to sit below the bleed nipple. I have just put new pistons, seals in and cleaned the calipers out until they are spotless. Hopefully this will sort it. I have seen someone mentioning putting food colouring in the new fluid but don't think I'll add any.

Cheers mate

Rob

When I bought my 5.1, I picked up 2 litres to make sure! I either have a full bottle left or 95% of one, though it was good to make sure!

When I bought my 5.1, I picked up 2 litres to make sure! I either have a full bottle left or 95% of one, though it was good to make sure!

Good thinking I've just bought 2 litres and have new pads in so I'll save some of the 2 litres to top up as the pads wear.

cheers

Rob

Nice one my purchase was in conjunction with a full brake fluid change when swapping from j-spec to uk spec brakes!

Depending on what you buy, some can be used as transmission fluid too if required...

some can be used as transmission fluid too if required...

really?

I maybe read it wrong, I'd have to check!

I'm also out drunk, probably doesn't help being on here and possibly thinking things incorrectly!

edit: Also just realised that you probably meant the clutch hydraulics NOT the transmission

I have just done mine and could do with some clarification,

I took out the the master cylinder and res, I emptied the old oil into a 2 litre milk bottle after this I gave it a clean as the oils was BLACK! (Thanks to previous owner not doing any servicing)

After this I reconnect the res to the master cylinder and attached back to the car filled with brake fluid and then bled the master cylinder

After this I then reconnected the brake lines and started to bleed the brake in the following order

Near side rear

Off side rear

Near side front

Off side front

I got all of the air out of the line except for the near side front all I kept getting was very very tiny air bubbles (hard to see)

Anyways I tightened the nipple and placed the wheels back on and took her for a spin

Now I can't remember what the brakes felt like before so I can't really compare them or exposing it for that matter but I just don't think that they seem right (possibly them really tiny air bubbles, not sure) but the car does stop fine I think, I just took it straight to 120 and hit the brakes and it stopped (thank god)

Would you say that they were fine or not its the first time I have ever done anything like this and just not sure

I bought 2 litres of brake fluid and used just less than 1 bottle doing the full system and according to the oils thread it states that the dry capacity is ~1.5L's now apart from the master cylinder I just pushed out the old oil with the new, and some of the new went in the same milk bottle so I would assume that I should have at least used 1 full bottle but all the fluid is coming put clear

I'm not sure if I have done this correctly or not any advise would be helpful

Pete

Sounds like you've done a thorough job on that. I had those tiny air bubbles on mine, first time I did the bleed...there were thousands of them. Must have bled the caliper about ten times. Those really hard to see bubbles might actually be from the air getting in near the bleeder valve, where you connect your hose to the bleed nipple.

I ended up using about 2.5litres, but that's because I couldn't get rid of those tiny air bubbles. If the fluid is coming out clear all four sides then it means you have successfully pushed out all the old fluid, and new fluid is coursing through its veins

Thanks that's put my mind at ease and the bleed nipped was very loose where I was getting the tiny air bubbles from so you might be on to something there will have to try it a little tighter next time and see if they are still appearing

Thanks again

Thanks that's put my mind at ease and the bleed nipped was very loose where I was getting the tiny air bubbles from so you might be on to something there will have to try it a little tighter next time and see if they are still appearing

 

Thanks again

That's the mistake I made the first time, opened the bleeder screw quite a lot, somehow it still lets bits of air in. Seen a guy who puts a cable tie on top of the hose so it fits snug, so it minimises those tiny little bubbles. Bleeding the brakes over 10 times each has taught me to open it no more than a quarter turn, bit less infact - more than enough for bleeding. I just got my mate to push the pedal down, I released the bleeder valve - pedal goes to the floor, I close it up and he lets of the pedal - repeat. All of this with the hose in fresh brake fluid so no air can get it. Bled my rear UK calipers this weekend and it took me 4 minutes per side

1) use a vacuum bleeder, it's about £25 and makes brake bleeding an order of magnitude easier (and you can do it on your own).

2) Blob a load of grease around the bleed nipple and bleed hose to seal it against those tiny air bubbles

I will have a look into the vacuum bleeder for when I get my new brake kit and see how that goes if it really saves time then I will probably invest it one, but for now I'm going too stick to the manual method and come Friday will double check all of the brake lines for air bubble only turning the nipple ever so slightly and will see if I have any tiny air bubbles then also I bought the halfordsn1 man bleed kit cost me £5 and if I knew what was in it I would have made my own for less than £1

The one man bleed kits come in different variety, I bought one for a tenner from machine mart that connects to an air source like a spare wheel, it automatically pushes fluid through the system. Pretty good, but the brake fluid reservoir cap didn't fit on the supe so was a no go. Bled my daily driver with it though, was very easy to do, quick too!