rangerovers.pub
The only place for a coil spring is up Zebedee's arse
Member
Joined:
Posts: 449

After a wait of several weeks, my new hoses arrived yesterday so I fitted them up this morning, ready for the great brake bleed.

Remember I'm starting from an empty system.

Step 1 in RAVE, as you’ll all obviously know, is to bleed the master cylinder. “Open bleed screw on booster, when fluid appears, close bleed screw” etc., etc.

Reservoir is full but, I’m getting no fluid at the bleed screw.

Any ideas?

I've mailed Russell to see if he's come across this before after a modulator rebuild.

Member
Joined:
Posts: 2312

Had this on the black one. After taking bleed nipple completely out and cleaning (no change), I just tapped the pedal lightly and fluid appeared.
Just one of those P38 quirks I think.

Member
Joined:
Posts: 449

Yeah, I tried the pedal bit but nothing.

Russell responded not to worry too much and crack on with the rest of the bleed. Says he's had it before.

I'll resume in the morning.

I was just worried I'd done something wrong in the rebuild, but the modulator only really goes back together one way, and the pedal is super smooth.

I'll report back!

Member
Joined:
Posts: 449

Now I am stumped.

Went on to bleed the front caliper and nothing. Went back to bleed screw 1 and nothing. Messed around for a bit then gave it some ignition. Pump fired up no problem and I’ve got fluid at the “High pressure” bled screws high up on the modulator, but still nothing at the original one or the caliper.

Seriously confused.

I’ve gone back mentally through the mod rebuild and happy that everything went back as it came out so I’m very confused. You’d think gravity would do half of it!

Member
Joined:
Posts: 2312

That's a weird one George. The fronts operate on the hydrostatic AND power systems so you should get something. Don't suppose you've got a vacuum bleeder handy?
Just looking at the fluid flow info:
Hydrostatic circuit - Consists of servo cylinders
supplied by master cylinder pressure. The front
calipers are supplied with direct hydraulic energy from
the servo cylinders, comprising a combination of
master cylinder pressure
and direct hydraulic power.

So, for some reason the master cylinder isn't getting/ supplying fluid

Member
Joined:
Posts: 449

Weird it is indeed.

If I stick ignition on, then crack the banjo union, there's fluid there and also at the top two bleed nipples. Just nothing on the "Low pressure" side.

Unfortunately no artificial aids, just me on the calipers and the eldest girl on the pedal.

Member
avatar
Joined:
Posts: 5429

Did the brakes on a '95 Classic (the soft dash one that is a sort of hybrid Classic/P38/Disco) recently that had been completely stripped out to have a new bulkhead welded in. Although a different part number the modulator works in just the same way as the P38 one and the bleeding procedure is identical. We couldn't get anything out of the hydrostatic circuit at all. No amount of pedal pumping did anything and even leaving a bleed nipple out and letting gravity do it didn't work. There seemed to be no flow between master cylinder and calipers. Then we found that as soon as the ignition was turned on so the pump ran, the brakes locked on. Had to open the bleed nipples to release the pressure to move the car. Disconnected the fork from the pedal, gave it a wiggle a few times, tried pulling it out (but it didn't appear to move), reconnected it and all was fine.

Member
Joined:
Posts: 449

Give that man a coconut!

Obviously something missing from RAVE; "Wiggle the fork" and guess what? Fluid from the nipple. Praise the Lord it's a miracle.

Don't know about the rest yet as I've come upstairs for a re-hydrate, but I'll be heading down shortly.

Cheers Buddy, you're a life saver!

Member
Joined:
Posts: 449

Success!

We haz brakes. Not as good as I'd like but commensurate with the amount of DOT4 available to me (3.5L - it's hard to find here) so she will stop and it'll do for the short trip from one abode to another tomorrow morning. When I source more fluid, I'll re-do the bleed.

Thanks again Gilbertd, you are officially my current hero!