K

kapilamuni

Active Member
Hi,
Today on my way to office I got the 'low brake fluid' warning randomly. I didn't care expecting to get to the office and have a look. But after about a Km the brake warning light flashed. Then I stopped the car and bought a can of brake fluid from a near by service station. The whole 1 ltr can went in and then I noticed that there is a leak from the right rear wheel. So turned back and headed home and after a while total loss of brakes.Somehow managed to get home and I'm going to look into this during this week end.
My questions are,
don't our cars have a front/rear pressure distribution valve like other cars?
How come I didn't have brakes for front wheels, at least?
thanks in advance.
 
Which Range Rover???

They should all have a split system, front and rear on separate circuits, so failure in one will mean the other can keep working....

Most modern fluid reservoirs will have separate sections (an internal divider) for front and rear, so if the rear brakes drain the tank, there will still be fluid available for the front system and vice versa.

On something like the Range Rover with its high kerb weight and bucket loads of momentum, when one system goes down, the effort required on the pedal to stop is exponentially increased....

Did the pedal drop to floor with no resistance, or was there just no feel and a very spongy pedal??
 
It will keep working on the other wheels but if the fluid is ****ing out every time you press the pedal - and bear in mind the pump will sense the drop in pressure and try to pump it up forcing even more out - it will eventually dump so much fluid none of them will work. It is designed to stop catastrophic failure of the brakes rather than seal itself so you can limp home.
 
If it is P38...I am sure it must have a fail safe circuit if one circuit is leaking....

The L322 uses a convential Servo and ABS boost pump.....tank has an internal divider for the two separate circuits...as does the 110 and the Ninety....

My '93 Classic had a similar braking system to the P38.....using a pump etc....and I can't remember the P38 despite having owned 4 of them!
 
Well I can certainly state that when I had a leak (burst pipe rear left) shortly after the 'Low Brake Fluid' warning, the system that came into operation was a) discover pressing the brake pedal does nothing , at all, ever b) employ left hand to rapidly operate hand brake, and c) deploy additional mental strength to certain sphincter muscles. :)
 
Saint.V8 said:
If it is P38...I am sure it must have a fail safe circuit if one circuit is leaking....

The L322 uses a convential Servo and ABS boost pump.....tank has an internal divider for the two separate circuits...as does the 110 and the Ninety....

My '93 Classic had a similar braking system to the P38.....using a pump etc....and I can't remember the P38 despite having owned 4 of them!
Click to expand...

It is a split circuit, IIRC. Usual diagonal split. But once the fluid starts to go I don't think it ever goes, ah, time to shut that valve. Certainly when you're bleeding the brakes and use the power part it just seems to keep pumping unless you turn the ignition off after 6 seconds.
 
Zorro587 said:
Well I can certainly state that when I had a leak (burst pipe rear left) shortly after the 'Low Brake Fluid' warning, the system that came into operation was a) discover pressing the brake pedal does nothing , at all, ever b) employ left hand to rapidly operate hand brake, and c) deploy additional mental strength to certain sphincter muscles. :)
Click to expand...

If you can knock a few diamonds out that might help with the cost of upkeep. :)
 
Grrrrrr said:
It is a split circuit, IIRC. Usual diagonal split. But once the fluid starts to go I don't think it ever goes, ah, time to shut that valve. Certainly when you're bleeding the brakes and use the power part it just seems to keep pumping unless you turn the ignition off after 6 seconds.
Click to expand...
Yep ,just reading....it is split, but front to rear....

Rear circuit is Power fed and the front is Power and Hydrostatic fed.

The tank is divided to feed both the power circuit and the hydrostatic circuit....but the way it is piped is as you say. If there is a leak in one circuit, the pump will drain both chambers....how fecking stupid is that!!??

P38_BRAKE_CIRCUIT.jpg
 
Think it may have been wiser to stop driving, specially as it took a litre to fill it and it was peeing fluid out. Loss of brakes was a pretty predictable outcome. Removing pressure pump relay would have left him with hydrostatic at front, rears are not active without pressure.:D:D
 
Last edited:
Saint.V8 said:
Yep ,just reading....it is split, but front to rear....

Rear circuit is Power fed and the front is Power and Hydrostatic fed.

The tank is divided to feed both the power circuit and the hydrostatic circuit....but the way it is piped is as you say. If there is a leak in one circuit, the pump will drain both chambers....how fecking stupid is that!!??

View attachment 99089
Click to expand...

Clearly they were learning as they improved the next generation. It is still a pretty clever braking system, especially for its age.

:)
 
wammers said:
Think it may have been wiser to stop driving, specially as it took a litre to fill it and it was peeing fluid out. Loss of brakes was a pretty predictable outcome. Removing pressure pump relay would have left him with hydrostatic at front, rears are not active without pressure.:D:D
Click to expand...

Now that's a tip worth remembering. Maybe ought to jot down the relay number somewhere so I can remember it. Mine's over 20 years now so I should probably think about replacing the lines as preventative maintenance.
 
Grrrrrr said:
Now that's a tip worth remembering. Maybe ought to jot down the relay number somewhere so I can remember it. Mine's over 20 years now so I should probably think about replacing the lines as preventative maintenance.
Click to expand...

That is why if the lift pump dies i would always say take the tank out if the brake lines have never been done. It makes life so much easier. :D:D
 
wammers said:
That is why if the lift pump dies i would always say take the tank out if the brake lines have never been done. It makes life so much easier. :D:D
Click to expand...

Yes, I did have a look while I had the tank out. They didn't look too bad. They are starting to show signs of corrosion though. MoT tester noted it.
 
Grrrrrr said:
Yes, I did have a look while I had the tank out. They didn't look too bad. They are starting to show signs of corrosion though. MoT tester noted it.
Click to expand...

If you are splicing to the original LR pipes using a female female coupling use a flaring tool with grip ridges. The original pipes can be a bitch to flare. My Ridgid tools flaring tool won't do them it has no pipe grip ridges in the 3/16 harbour. They just slide through they are so hard. Bit of a bugger for such a good unit.
 
wammers said:
If you are splicing to the original LR pipes using a female female coupling use a flaring tool with grip ridges. The original pipes can be a bitch to flare. My Ridgid tools flaring tool won't do them it has no pipe grip ridges in the 3/16 harbour. They just slide through they are so hard. Bit of a bugger for such a good unit.
Click to expand...
I had to relace all the rear pipes and the two front to rear's on my black one, there are female couplings under the o/s/f arch liner. Still took 4 mtrs of pipe per front to rear run.
 
tomcat59alan said:
I had to relace all the rear pipes and the two front to rear's on my black one, there are female couplings under the o/s/f arch liner. Still took 4 mtrs of pipe per front to rear run.
Click to expand...

I spliced mine just after air tank, thinking back it may have been better to do them right to the front couplings. The only ones that were bad were the small Z shaped ones at either side and the one across the back to N/S that was knackered came out in three pieces just fell apart.;)
 
Never made brake pipes before so another learning experience when I get around to it. I was planning on replacing the whole line rather than patch it. Noted: 3/16 ridged flaring tool. Not sure how easy that'll be without it in the air though. I keep wondering how long the rubber in the modulator can last as well.
 
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