Good Morning.

Tuesday I intend to change brake fluid (apparently something which should be done on regular basis ? (annually ?)) .
I want to also check / adjust 'load proportioning valve' and check/adjust pressure front & back.
This second bit is where I have and issue, I have been told that there should be a plate / sticker on inside of door (or under bonnet) which displays values for bar pressure expected in system for given axle weight of vehicle.
no I cannot find said plate and with no manuals I also have nowhere else to look !

Anyone of you guys with similar vehicle able to help me out ?

And, just a though ? how crucial is the 'load proportioning valve' ? could it be disconnected ?

Your thoughts suggestions as always awaited and appreciated.

Phil. (converted ex-RAF shortbase 35-10 4x4)

as far as I am aware the load dependant brake valve opens more as you put more weight in your vehicle, thus allowing more fluid to reach the wheel cylinders, giving you more stopping power. dont think you should disconect it though as it is there for a reason.
as for changing fliuid every year that is a bit ott....brake fluid is hydroscopic meaning in takes in water and then is not pure anymore so does not do the job properly. I would say to change it is a good move if you notice spongy brakes.
I have a copy of the manual in pdf courtesy of luke so can pass it on if you can accept large files

Graeme

Hey Phil, have you checked your FTP site recently?
It worked this weekend. Pity you couldn't make it, after the crappy week the weather Saturday was perfect.

Graeme's right more load = more rear braking. There's a pushrod coming up off the diff connected to the lever of the distributer.

The flaw in the system is that the braking distribution is changed as you go over a bump because the suspension moves

The lever to my proportioning valve broke on some potholing section in Africa;all the braking power went to the front, the consequent nose diving of the truck was scary to say the least.
With an overland vehicle whose contents don't change much you can just physically jam it on max (mine's done with a mole grip) and disconnect the pushrod from the axle. It's one less thing to go up and down with the suspension.

Enjoy
Luke

Did you get the brake warning light sorted? The spaghetti described in the electrical manual takes a lot of staring to understand.

I agree with Graeme and Luke; these valves are connected to the rear axle to determine the vehicles load situation according to the deflection of the rear suspension, thus automatically proportioning the amount of braking to the rear to avoid rear wheel lockup under heavy braking. However the system is designed for delivery vans which can be running empty, ie light on the rear end so you could lock the rear very easily if there's no proportioning valve. Once you convert it to a camper you will be running near or on (did someone say over??) max weight all the time anyway so the valve becomes less relevant.

My WM runs air suspension at the rear so hasn't got the sag of laden leaf springs, it has an extra pressure valve which leaked so I chucked it years ago and sometimes I forget the air is down after levelling on an overnight stop so drive off on the bumpstops. Yet it brakes fine, wet or dry, and will only lock the rears in a real emergency situation. (Don't ask how I know........!)

I've changed the fluid three times in eight years.

Nigel

Luke : sorry couldn't make it, really wanted to but alas Friday just dissappeared, it's amazing how even though i have all my own time I still manage to run out of time. !!!!
Thanks for the manual - excellent ! just 565 pages to browse through on those long cold winter nights !!!
Yep - brake warn light not actually fixed, but i found the cause, shorting of a cable to pads. No probs, now I know it is only the std 'pad low' warning light (and that nothing else can trigger it) I am much happy. Pads replaced about 8k kms back. - so cheers for that.

Nigel - what is max weight ? i mean specified for these SWB 35-10s 4x4 ? (as opposed to a definition of 'max weight' !!). Put mine on a weghbridge today, comes in at 4,200kgs if I have all liquid tanks full.
Have i reached max yet ?????? mmmmmmm

OK down to specifics, as a test i did disconnect the push rod that's connected to diff and manually 'tied' it up, to be honest I was guessing a bit and I was not sure if I was wedging it open or shut !!! anyhow, did that about 2 months back and to be fair I can't say I noticed any difference. Which I guess would indicate what Nigel says with regards to weight already keeping valve open.
So conclusion i think is to leave connected for now, but if it ever snaps or buggers I think I will be ok to wedge open.

BUT BUT BUt - my other issue is the balancing of the pressure front to back (issue being I don't have the chart/table/plate/sticker which shows pressure expected based upon weight).
Tomorrow I change fluid (interesting NIge that you change so regular, it's not something I have ever thought about and no garage has ever suggested to me !) , which will now be part of the bi-annual maintenance jobs.
But, I'm fairly certain that with my weight now known (and probably now different) the pressures between front and back will be 'wrong', ideally, I would like to check and adjust.
I know this garage i'm at tomorrow can test pressure but i need a reference (i.e photo from inside of one of your doors !!!!) to check against.

So, clock's a tickin here guys !!!! i am under truck at 7.30am tomorrow !!

cheers to all
Phil.

Hi Phil, I have mailed you. and I did manage to up load manual if you look on P8 of the brake section the details you require are there! no need for any photos me thinks!

good luck and let us all know the results

Graeme