back brakes lockup

[glanrichbex]

Hi all,

Subject of the thread explains it really. On a dry road I don't have a problem but in the wet it feels like the back brakes are hyper sensitive and lock up easily.
A guy I work with tells me there is a pressure limiting device which is in line with the rear hydraulic circuit ..... I can't find it and as others have alluded to in other threads here, it ain't the time of year to be laying on the drive under trucks.

Can someone please tell me the location of this device so that I can view it and see what I'm dealing with.

Many thanks
Rich

 

[RJL Services]

follow the brake lines from the front to the back up in the drivers side wheel arch area behind the wheel just by axle should be a load sensing valve with a lever and spring going to axle make sure it moves freely

 

[Lazy-Ferret]

It's on the drivers side, directly above the rear axle, bolted to the inside of the chassis... if you have a body lift, you can see it with out getting under the truck looking through the gap between the body and chassis. It has a large spring, about 6 inches long, and an inch in diameter, that goes from it, to the back axle.

Hope that helps...

 

[elty001]

Nissan did away with the load sensing valve from around 2000 onwards so don't be alarmed if you can't find it.

 

[Mav96]

I removed my sensing valve when I done my brake lines, no problems arose.
Of course your problem could be the front brakes not working correctly putting more pressure on the rear, had that on piece of junk I used to drive years ago.

Best way to find out go to an Mot testing place & see if you can try your brakes on the rollers :nenau

 

[glanrichbex]

Many thanks all, Apologies for not replying sooner - some reason my password was being rejected??? anyhow - she's a 2005 so as has been said by elty001 - the device is unlikely to be there, I've had another look but I can't see it.
I renewed my front discs and pads 6months ago thinking this could be the problem, the callipers seemed to be in excellent working order so assumed it must be too much pressure to the back brakes.
I had to totally rebuild the back brakes with all new parts as both sides were leaking fluid. The problem did go away for a few weeks but I now think that could be that they were inefficient when the shoes were bedding in.
Now it's all back to the way it was before :doh with hyper sensitive rear brakes that lock up in the wet.

 

[solarman216]

Damp linings from brake fluid will cause temporary over efficiency of drum brakes when cold, but I think I will put my money on a problem with the front calipers/disks, Rick