How often do rear brake proportioning valves fail?

[VolvoLatAm]

non abs 240s pn 1228738
https://www.skandix.de/en/spare-part...4-bar/1014313/

I have asked around for consensus whether or not these parts fail due to exterior rust or interior clogged valves from dirty fluid with debris...got different responses

Since they are no longer made, I am curious what TB owners are going to do? Install used ones? They are 34 bar...are people going to run adjustable rear proportioning valves from summit racing or something? (getting the exact pressure right by self adjusting seems impossible)

You can rarely find them nos, but they cost more than some cars for 2 of them:
https://www.ebay.com/itm/36348287697...oAAOSww3Fepjzf

[142 guy]

You can find new ones. Scandcar lists them for a nose bleed price. The earlier valves as used on the 140 could be taken apart (4 bolt flange held the top hat on) and you can buy rebuild kits for them. The top hat on the 2 series appears to be crimped on so clearly not intended to be serviced. If you did pry off the top hat you would have the hassle of resetting the spring which is perhaps why they do not appear to list rebuild kits.

I pulled the valves off my 1971 142. Put plugs in the ports and sandblasted the outside clean and then disassembled and cleaned the internals. Didn't use a rebuild kit. Made sure not to touch the top hat adjusting screw. Painted the outside with Eastwood extreme chassis black and stuck them back on the car with new brake lines. They work - as far as I know. Push comes to shove you can delete them and install a bulkhead fitting for the flex to hard line connection. Put in a proportioning valve if you think its necessary. You could also find a pair from a salvage 140. At least those a rebuildable.

[Redwood Chair]

Generally speaking they're only bad on cars that have sat unused for some time.

Originally Posted by VolvoLatAm

Since they are no longer made, I am curious what TB owners are going to do?

Go to the junkyard like we always do or beg in wanted if there's nothing around locally.

Originally Posted by VolvoLatAm

Install used ones?

See above.

[Radtap]

Wait until a 91 pops up in the junkyard and pull the octopus from that, has no sensor like the other years and instead uses a sensor on brake fluid reservoir, you don’t need a light on your dash to tell you that you’ve lost brake pressure. The 91 octopus will never leak

[VolvoLatAm]

Originally Posted by Radtap

Wait until a 91 pops up in the junkyard and pull the octopus from that, has no sensor like the other years and instead uses a sensor on brake fluid reservoir, you don’t need a light on your dash to tell you that you’ve lost brake pressure. The 91 octopus will never leak

not the octopus

[VolvoLatAm]

Originally Posted by Redwood Chair

Generally speaking they're only bad on cars that have sat unused for some time.



Go to the junkyard like we always do or beg in wanted if there's nothing around locally.






See above.

a car in a junkyard would probably be one that has sat unused for some time

[Redwood Chair]

Originally Posted by VolvoLatAm

a car in a junkyard would probably be one that has sat unused for some time

Not around here they crush them within 30-45 days.

[VolvoLatAm]

Originally Posted by Redwood Chair

Not around here they crush them within 30-45 days.

https://forums.turbobricks.com/showthread.php?t=354006

seems like the solutions are not very good

[Redwood Chair]

Originally Posted by VolvoLatAm

https://forums.turbobricks.com/showthread.php?t=354006

seems like the solutions are not very good

IDK if you're worried about it find a 'fresh kill' with collision damage and the proportioning valves will very likely be fine here in Cali.

If they're not you have 30 days to return them for another part or a credit slip for another pull at the JY slot machine whenever you choose to use it.

Unless you're being silly and expecting any kind of a guarantee with 30+ year old car parts, NOS or otherwise.

[VolvoLatAm]

Originally Posted by Redwood Chair

IDK if you're worried about it find a 'fresh kill' with collision damage and the proportioning valves will very likely be fine here in Cali.

If they're not you have 30 days to return them for another part or a credit slip for another pull at the JY slot machine whenever you choose to use it.

Unless you're being silly and expecting any kind of a guarantee with 30+ year old car parts, NOS or otherwise.

again assuming everybody on turbobricks lives in the U.S.

Live in Medellín, Colombia. Volvos here were owned by cartel members here in the 80s, they were luxury cars and there are not many of them.

[Redwood Chair]

Originally Posted by VolvoLatAm

again assuming everybody on turbobricks lives in the U.S.

Live in Medellín, Colombia. Volvos here were owned by cartel members here in the 80s, they were luxury cars and there are not many of them.

That's why I mentioned posting in wanted for 'known good' which is always cheaper and often times better than NOS which only means "It hasn't been sold in a retail setting" nothing more & nothing less.

EX:

It can be sitting on a wet shelf for 30+ years and have shelf wear / be rusty or have been stored in a hot attic and have dried out seals & O rings.

[Radtap]

Originally Posted by VolvoLatAm

not the octopus

pfft didn't look at the part #, im going to the junkyard this weekend and there was a 244 with the valves still there last I checked if interested

[2turbotoys]

I just replaced them with a pair of SS front brake lines. Direct replacement, but not everyone is going to be comfortable with this.

[Redwood Chair]

Originally Posted by 2turbotoys

I just replaced them with a pair of SS front brake lines. Direct replacement, but not everyone is going to be comfortable with this.

With big brakes that's what you do to keep the bias balance in the ball park.

[2turbotoys]

Ya it was on my R brake swap.

[adamdrives]

I recently had a pair on an 84 turbo that wouldn't allow any brake flow at all. Couldn't find replacements so I blasted them with brake clean and compressed air and they regained flow. not sure if theres a diaphragm or spring in piston in there so I'm not sure if it was a good idea, but it worked.

[Redwood Chair]

Originally Posted by adamdrives

I recently had a pair on an 84 turbo that wouldn't allow any brake flow at all. Couldn't find replacements so I blasted them with brake clean and compressed air and they regained flow. not sure if theres a diaphragm or spring in piston in there so I'm not sure if it was a good idea, but it worked.

Probably not the best idea to introduce petrochemicals into the braking system, but carry on...



And yes it's a spring loaded rising rate joker valve.

[Janspeed]

are those proportioning valves specific to the car? If not why not pull/get/install/use one from a similar RWD car or pickup truck ?

[VolvoLatAm]

Originally Posted by Janspeed

are those proportioning valves specific to the car? If not why not pull/get/install/use one from a similar RWD car or pickup truck ?

you would have to find ones with the same fittings and pressure. If anybody did here there would already be a swap solution to a part still being produced...

[Radtap]

I’ve seen people replace them with an octopus block with the extra ports blocked but then you’ll have a little more brake pressure in the rear than usual, can be done if you’ve upgraded front brakes

[Redwood Chair]

Originally Posted by Janspeed

are those proportioning valves specific to the car? If not why not pull/get/install/use one from a similar RWD car or pickup truck ?

Originally Posted by VolvoLatAm

you would have to find ones with the same fittings and pressure. If anybody did here there would already be a swap solution to a part still being produced...

Similar units can probably be found on German cars but they're very likely more expensive than the Volvo ones.

[Andrewhans]

Well... that's interesting. Is it really that simple to delete the bias valve? Which front lines? ABS or Non ABS car front line? Any brand you like?

Originally Posted by 2turbotoys

I just replaced them with a pair of SS front brake lines. Direct replacement, but not everyone is going to be comfortable with this.