URGENT- Why are the rear wheel cylinders sided.

Right for those who haven't already read my other brake threads, I am having a real pig of a job getting my van through an MOT on rear brake issues.
I've dealt with my original problem (no brakes) with a replacement compensator. Now my O/S brake is seriously over braking. I've fitted new wheel cylinders from ebay. Both are the same but the original ones are sided. I'm guessing this is my issue but theres another listing on ebay which says the wheel cylinders will fit either side.
Can someone confirm they are definitely significantly different.

I had similar problem with MOT a while back. I think they're sided as one side has fluid in and fluid out (no bleeding valve), and other side has fluid in and bleed valve.

Got round it by splitting pipe into left and right with a t-piece, feeding to cylinders each having inlet and bleed valve.

Sorry it's a rushed answer but dinner is on the table......

I've fitted the bleed valve in the n/s cylinder and the pipe (the one that goes to the n/s) to the o/s cylinder without a problem, its just the over braking which made me wonder if the internals were different.

I seem to remember that if they are universal side cylinders, that you need to split the brake pipe before the cylinders and run them in parallel basically like has been mentioned by PFM...

sided cylinders have a valve to allow a certain amount of fluid to bypass the first cylinder I believe...

Hi the only difference is one side has the bleed one doesn't most cylinders come in the box with a couple of blanking plugs and the valve as a seperate bit and the cylinders are the same, it is also common to go into one cylinder and across the live axle on pre 80's cars.

rich/difflock thanks for the answers both very different, I like difflocks as it'd mean i'm not going mad but the two originals i took off seemed to look pretty much the same. I've found a place online who stock sided ones. I'll give them a call tomorrow see if they can compare. £130 it'd cost me for a pair from piaggio/diahatsu, ouch.

a new brake pipe custom made for you at a local autofactors would cost you less than £20 I suspect.....

I got one made for the rear of my Landy...
I think that cost me £13 with fittings and posh splitter block (nice big heavy duty brass one so it will take a bit of a beating....less likely to fail off road then )



I definitely wouldnt go and buy more cylinders though......

Got confirmation cylinders are definitely the same. Checked the ones fitted today to make sure they were the right ones. stripped and cleaned both drums again and bled as best as I can on my own. Also took the lever completely off the comp valve. put it back on the rollers and now the rears are just about even but under braking. Can anyone confirm if the comp valve lever should be touching the pin on the valve when unlaiden.

Thanks

I can't remember but when unladen there should be no load on the valve and when max laden it should be all the way in, if the valve moves I would be tempted to fix it fully in to get the test and then sort it out when you have time mine is seized on max brake pressure and I'm not bothering to sort it out.

I know people bypass the load sensing brake valve on a lot of vans...

its only supposed to stop as much braking power going to the back wheels, because with nothing in the back, you could lock the wheels easier....


at least it seems to be partially sorted though

I would do as Rich said, and force it to stay open.