Exhaust hanger missing, LSPV & Waxoyling

Hi again, so I have got my new exhaust pipe but unfortunately it has one less hanger than the original one. It is the one next to where it bolts on to the cat pipe. Do you guys think it will be ok without it as there is another one a bit further down the cat pipe?


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Also as my little van failed the MOT on rear hydraulic brakes not coming on I was trying to take apart the drum brakes to see if the pistons inside are not stuck but I was having difficulty getting off the outside bit (brake drum). I could get it to move a bit but it was not going to come off without some force. Is there something else to undo or should I just force it off?

Then I noticed the LSPV behind the brake, the spring arm attached to the axel goes up and down easily enough but should this be pushing a piston up into the LSPV main body to regulate the braking? If there is a piston pushed up by this arm it is jammed up in the LSPV. (Though I don't know why this would stop my rear brakes working)

And finally waxoyling
While I'm under there I thought I may as well start wire brushing rust and dirt off in preperation for waxoyling. Is it enough just to brush off the worst of the dirt and rust before spraying with waxoyl? Or should I wire brush and then give it a thorough spray wash with hot soapy water and rinse off. I have been looking at a 5 litre pump spray on ebay for £10 but I'm not sure what detergent is best.

As always, thanks for the invaluable advice from you most helpful people.

Stephen

Are all the hangers identical otherwise? If so I wouldn't worry too much about that one being missing.

The back brakes not working is very common, and its pretty much always caused by that bastard rear pressure valve thing you've found. You can often get them to pass the test if you adjust the bottom bolt on the arm to put more pressure on the spring, and take it to the test with loads of weight in the boot like some paving flags, tool boxes, bags of heavy crap etc. But to test it is that you should do the following:-

First jack up the back of the van via the rear axle - so the weight is still compressing the springs.
Then get someone to press the brake pedal while you spin the back wheels, see if you can feel the brakes kicking in a little bit.
Next push the pressure valve arm against the valve while you spin the wheel and see if you can make the brakes kick in.

If you can make them kick in, all you need to do is somehow modify the valve and arm assembly or put more weight in the back of the van.

It also helps if you take the rubber boot off the valve and squirt it with wd-40, then work the piston in the middle as the get stiff due to lack of use and weather conditions.

As long as you can make the valve actually open so the brake work you can do many a naughty trick to make the valve stay open for the test, maybe a stonger spring from an engineering shop, or a longer rod I never said this though right?

For the wax oil sort of task, personally I prefer shultz underseal but it's more messy to use. Just wire brush off the major lose stuff and coat it up.

Thanks for the reply

Should the arm be pushing a piston up into the LSPV as currently it moves but does not seem to be attached to anything except its own pivot?

Exactly, that's why they fail the MOT on rear brakes. Until there's some weight in the back the rear brakes hardly do anything.

Because they never get worked they get stiff inside.

And the spring rusts making it really weak.

Half the time if you sit someone who's chunky pie, or a few tool boxes and a wakka plate in the boot the valve opens and the brakes work.

Is that stiff inside the drum or the LSPV?

LSPV, drums are normally fine and the brake shoes and drum show very minimal signs of wear because the valve is never open

So its usually all down to the lspv then, what a pain.

Is it worth removing it and and cleaning it up or is that a big faff?

Then you'll have to do the whole bleed thing etc.

Before you jump into any assumptions, jack the van up via the axle so the weight is still compressing the springs, then with a handy assistant press the brake pedal while you put pressure on the valve and turn the wheels. See if its totally stuck closed.

If you can't make the brakes work with pressure on the valves actuator then you need to dig deeper and take the valve to bits.

On an valve that still works, if you put pressure on the arm touching the lspv valve, when someone presses the brake pedal you can feel the arm fight back slightly.

Ok thanks I'll get onto that and find a chunky friend to help

When you take the drums off, take an angle grinder to the lip you will find around the edge of the drum, this will make it a lot easier to remove next time, should you need to. It's probably also worth checking if they are glazed inside (smooth and shiny) if so, sandpaper them and the shoes, just to give them that extra grip they should have.

Spot on about the LSPV, i did not understand how it was activated before.

I increased the spring pressure off the axel which presses against the bottom of LSPV and that did the trick, back brakes are now engaging. And if I need more spring pressure then I'll make a spacer from an old cotton reel chopped in two and zip tied in place.

No need for large lads jumping around in the back now i think

There are a couple of types of the valves Matt has a different one to the one fitted on ours the piston inside only moves out with the fluid pressure the other thing that can gum them up is the fluid going funny when ours had it's first MOT when we got it, it failed on the short pipe by the valve with excess rust when I changed it and bleed it the line was choked with a gungy fluid crap, the lspv on ours can be taken apart insitu but it does drain the fluid so put a tray under if you do, I did post pics of mine somewhere and Matt put his up as well.

Well they are coming on now, though its hard to tell how much. Enough to strain the engine a little when I brake with the back on jack stands and the wheels running free.

Hopefully enough to pass my mot anyway.

I think i'll just replace the brake fluid if it passes the mot.

How do you find bleeding the brakes, I plan to use eezibleed to push the fluid through but I gather the back bleeding screws can be hard to undo?

watch the pressure you use I have a ezi bleed and a spare cap to connect to and at 4psi it would still blow the cap off the master cylinder check the manuel but I think it is front left, front right lspv then left rear. the bleed valve on out lspv has snapped off so I just bleed straight out the back and as required

When bleeding any vehicle with an LSPV, I find I have much greater success if I cable tie the valve open first.

i think i will use a mountain bike tyre for the eesibleed.

is it hard to find the bleed screws on the lspv and rear drums?

it looks like one tube for the rear brakes that go through everything so i suppose in theory you can just bleed the last one. and i think there is a line from the front brakes to the lspv - not sure how you bleed that!

do you mean cable tie the lspv arm up to push on the valve?

the lspv is a high point so can get a air lock if it has been open but one valve is on it the other is next to the pipe that feeds it. As for the tyre you do need volume not just a little pressure I had Clare putting the valve on as i needed just stop the cap from leaking or popping off.

I don't use easy bleeders on anything, first I use gravity till I get some fluid coming out somewhere, then I do the old pedal pumping game.

pedal pump is fine if there are no air lock spots I always finish with that same applies to gravity.