MK1 NOS brake compensator vs new one

Hi

Quick question: is it a bad idea to install a NOS brake compensator vs a new one? I've got eyes on a mint ATE unit, and a new one is about 60£ more. Seing it's a potentially 20+ year old item, I'm wondering if there are any seals that might have gone bad even though it looks fresh?
Sorry it's not megaurgent, but I could really appreciate someone's thought on it.. Thanks

A brake compensator, (we call them proportional valves) are usually no more than a oriface reducer and a Vane with an o-ring on ones that are load sensing (rear ones on a Dub, and Vans and Trucks over here.

NOS may not be better as dry o-rings for 25 years dry rot, and when you add new Fluid may swell and leak.

If the older one wasn't leaking there isn't probably anything wrong with it. The NOS isn't a known good thing off the bat.

The car didn't have it originally. In order to have an upcoming DX swap approved and registered here in Norway I have to upgrade the brakes to gti-spec. I already swapped for VW2 calipers in the front, and will have to get the larger bore cylinders at the back as well. Anyway thanks for letting me know, NOS rotted o-rings sounds like trouble to me..

Not say that the NOS is Bad, it just has been sitting on a shelf for god knows how long, and you don't know if the Lube they used is new or old.

On my Cabriolet, the proportional valves are on the MC for the rears.  And they are just a restrictor for the drums.  

I got a brand new ATE one here, think I paid £68 altogether, so it has gone up a bit since then.

https://www.mister-auto.co.uk/brake-power-regulator/volkswagen-golf-17-1-8-gti-112hp_v1628_g73.html

Still not too bad for what it is though.

It turns out I don't even have the bracket for the BFR on the car, the one that is welded to the floor…


In order to have the car registered with the DX engine however, I need the bigger 17.46mm rear cylinder for the drums, and therefore also a brake force regulator/pressure valve. Could you tell me the part number for the ones you have Briano? And what size drums/cylinders you have please?

look up the ETKA for a 93 Cabriolet, you will see the numbers.

http://www.oemepc.com/vw/parts_lst/markt/USA/modell/CONV/year/1992/hg/6/catalog/vw/drive_standart/44/lang/e

Thanks.. Judging by the drawing, it seems that both the valve and the spring loaded regulator is installed. Would you know if that's always the case, or is it possible to have just the valves?

I figure I could use the valves off a Golf 3 1H0698401, which are also 3/35, but not if they are supposed to work in conjunction with the spring loaded regulator...

The Spring loaded Valve assembly was originally used on a Golf after about 82 on, my 81 (westy) didn't have it.  My current Cabriolets 88-93 never had it.  

They all used proportional valves that were on the MC.  I don't know how well they will work on a non-cabriolet type of MC as my Westy had 2 ports, whereas my Cabriolet has 4.  

I mean come on a load sensing valve has major suckage… I had one on my Dodge Caravan, and it was part and parcel of the rear leaf spring assembly… so if it went bad you had to buy a new Spring…. I guess it was easier to put on and off.    NOT.

On my Westy the valve was part of a Distribution block that affixed to the fender under the MC.

ouch
https://www.onlinecarparts.co.uk/oenumber/811614151.html

Here is what the Wsty Rabbits used in the US.
https://www.ebay.com/p/VW-Mk1-Rabbit-Brake-Proportioning-Valve-OEM-179-612-451-a/17022264486?iid=163189869019&chn=ps

Cabbys have a slight variation on their braking setup due to the different weight distribution of their bodywork - I think the newer ones have no regulator but have the valves under the MC.

I have no idea on the regulations in your country but I imagine when they say it needs to be GTI-spec, they mean GTI hatchback of the same era as your car (its a hatchback, right?)

There's 3 important things: rear wheel cylinders, proportioning valve, any fixed reducing valves if fitted. I would have thought it makes sense to get these for the same spec of car, ie not mix-and-match the components; and I think your country's regulations are basically going to impose that requirement on you.

Yes my car is a 4-door tintop, so technically I should have installed the spring loaded BFR and the larger 17.46 cylinders for the drums, as i think this was the setup for all tintop gits?

The problem is I don't have the floor mounting for the rear BFR, so I was hoping to just install the valves instead if they did more or less the same thing. I'm also planning to install a 22mm MC and a 9" servo along with the VW2 calipers, but I'm not sure what to do with the rears now…

Even though mine's not a cabby, wouldn't it be better to have valves fitted than no bias at all? Then I could at least install the larger rear cylinders and say that regulators are fitted for the inspection. But yea it doesn't feel quite right mix-matching brake components either

As i understand it the gti compensator (near rear beam) opens and allows more pressure to the rear brakes when the car is loaded, the suspension compresses and pulls on the valve which opens it.  The cabby valves cannot do the same thing but must surely work in the opposite way and reduce pressure to the rear at all times..

As far as I know, proportional valves are open up until a given pressure, and then they start to constrict. So they would not reduce pressure until the brakes are pushed hard and thus reducing the risk of lock up.. If so I can't see why I shouldn't benefit from installing them, and the larger 17.46 cylinders. Please correct me if I'm wrong

If thats so i would think they would be more beneficial than the gti compensator..

they both do the same job, just in different ways. if you dont even have the steel bracket under the car welded to the shell for the load valve, then just use the post-84 cab/rocco inline pressure valves instead

The pressurizing valves are designed to keep residual pressure in the lines. If you google 'brake line residual pressure valve' you'll see that there are broadly 2 variants, one for drum brakes and one for disc. I would suggest that these are probably more critical for brake feel and action than the compensator.
As has been mentioned, the compensator reduces the force (fluid pressure) that is going to the rear drums when the car is not loaded, preventing lock up. Fill the car with people and stuff and the compensator opens to allow more force (fluid pressure) to the rear drums.

yes to be clear, the pre-83 cabrio and tintop has a load valve under the car attached to the rear beam, and 2 residual pressure valves inline with the rear pipes at the bottom of the engine bay just before they go under the car.

on the later cab/scirocco the load valve under the car is removed as are the residual pressure valves you mentioned, and instead inline type reducing valves are screwed direct to the master cylinder and rear brake lines fitted into them.

the scirocco 16v has different versions of the valves, but these are hard to get. plenty of late cab owners have gone for rear discs using the drum valves no problem mind, and the OP doesnt care either way as he wants GTI type drum brake setup

Very clarifying, and exactly what I wanted to hear. No need to learn how to weld fortunately

Ah by the way, the MC has 4 outlets so I will need to run t-pieces for the rear brake light switches.. Just to be 110% sure, does it matter whether the valves are before or after the t-piece?