Changing brake fluid

[t-tony]

@Jimbob_OD is correct 1 lltr.wiill be enough to refill the system.

Tony.

 

[Mike Fishwick]

I change my fluid regularly - every couple of years - using an Gunsons pressure bleeder, starting with air only, running down the reservoir until it is very low before filling the bleeder with new fluid. I then bleed the brakes, using either normal or blue ATE fuid - a different colour every time I do a bleed/fluid change. This allows me to see when each brake line is purged of the old fluid. As the hydraulic system is never left empty, the order of bleeding is immaterial, and I have never had any difficulty in bleeding.

The system holds betweent half and three quarters of a litre, but I often go round again just to use up all the fluid, as it does not store well after opening. Don't forget about the clutch!

I also use and old fluid tin with a hold drilled in the cap to catch the old fluid, although a wine bottle is also handy for this. Remember that whet can be knocked over will be . . .

 

[Nodzed]

But I just bribe the missus to get in the driver's seat while I'm twisting the nipple saying 'in' 'out' 'in' etc

Not sure we need to know this. .........

 

[DrWong]

Tomorrow, I’m going to be doing a brake fluid change using a Gunson Eezibleed.

I’ve had my callipers off for a refurb and to replace some sections of brake line.

Before removing the callipers I depressed the brake pedal halfway and wedged it in place as advised to on here.

This is probably a daft question, but at what point is it safe to release the pedal?

I assume it’ll be fine to do it any time now the calipers are back on and the bleed nipples tightened so air can’t be sucked back into the system?

You should be fine to release the pedal now that the calipers are back on and nipples tightened. I similarly held the pedal down whilst I refreshed my calipers last year. You’ll still need to bleed tho etc

I gravity bled, followed by a few pumps of the pedal and then holding it down with the stick whilst I undid/tightened the bleed screw.

 

[Duncodin]

I never heard of that 'wedge pedal down' before. Maybe it's supposed to reduce the amount of air that 'percolates' back up the pipes to reduce the necessity for bleeding? But I always bled thoroughly anyway.

 

[Peter1450]

I understood from previous posts that wedging the brake pedal in the halfway down position was to stop fluid leaking from the system whilst working on the brakes.

 

[Jimbob_OD]

@Duncodin @Peter1450 You’re both right. I did it to stop excess fluid spilling over my garage floor and to stop air being sucked into the pipes.

I’ll be flushing any remaining fluid out, replacing it and thoroughly bleeding tomorrow

 

[t-tony]

Exactly so @Peter1450

Tony.

 

[DrWong]

If you're on your own when bleeding, the wedge can also take the place of the helper who would hold the pedal down in the two-person process

 

[Jimbob_OD]

Help!! So, I’ve run into some trouble bleeding my brakes using an Eezibleed kit. No fluid (or air) is bleeding out at any caliper when I open the bleed nipple. The kit is definitely pressurising the reservoir as the level in the filler bottle drops when hooked up to the tyre (at 12 PSI). Any suggestions please?

Edit: I’m wondering if the master cylinder piston has stuck from being sat with the brake pedal depressed (see earlier posts)?

 

[Zephyr]

Not an expert but isnt the tyre aupposed to have 32 or more?
plus you may have opened your bleeder valves too much and air is being sucked in while you're bleeding the fluid.

 

[Jimbob_OD]

Thanks @Zephyr. The instructions say no more than 20 psi but general consensus online seems to be to use 10-15

 

[Jimbob_OD]

Given up for the day. Can only assume it must be the master cylinder - the calipers all have new bleed nipples and flexi hoses. No fluid will budge from the reservoir when pressurised and the bleed nipples opened on any caliper.

I did try and remove the master cylinder to have a look but couldn’t work out how to access the lower of the two mounting bolts. And dropped and lost my 13mm socket deep into the wheel well in doing so.

Not a good day…

 

[t-tony]

Very unlikely that the M/Cyl is stuck. NEVER had that happen. Try cracking the pipe unions at the ABS pump and see if you have fluid movement there. Did you check that the bleed screws are clear?

Tony.

 

[Jimbob_OD]

Yep @t-tony - all four calipers have brand new clean bleed screws on them.

I’ll try the unions on the abs pump after work tomorrow - thanks!

 

[Jimbob_OD]

@t-tony Thanks for the advice. Just checked all the ABS pump unions. There is good pressure into the ABS pump on both lines and good pressure out to the two front calipers. No flow at all to either rear brake line. I’m guessing it’s new pump time and it’s not a serviceable part?

 

[t-tony]

Have you tried bleeding the rear brakes using a second person operating the brake pedal? That would be my next move.

Tony.

 

[Jimbob_OD]

I’ve not. I’ve only tried with a bleeder kit. I’ll see if I can get someone round. If all else fails, I’ve found a pump on eBay from a breaker for £20 which I can swap my ECU onto and swap over. Access for removal and replacement looks pretty easy (famous last words…)

 

[DrWong]

Have you tried cycling the ABS pump? I've had to do this before using INPA when I accidentally let the MC drain and air got in. From memory, the software activates both fronts together and then both rears together. I then bled the wheels individually afterwards, as normal.

Although there shouldn't be any need to do this because you pressurised the system using the wedge, so air shouldn't have got it. But it's the only thing I can think of.

 

[Jimbob_OD]

No, I don’t have the INPA software. I’m going to try T-Tony’s suggestion and if that doesn’t work, swap the pump out then take it to a local garage to have the ABS pump bled.

Thanks for your advice though.