Leaky combination valve
- Thread starter Skeltor
- Start date
- City
- Richmond
- State
- TX
Fairly certain that is a residual valve for the rear drum brakes. Drums brakes require slight pressure in the line to overcome the spring pressure on the shoes.
You could try buying a replacement valve and just replacing that part only. Having it leak there is just bad luck. But it should not be a common issue.
You could try buying a replacement valve and just replacing that part only. Having it leak there is just bad luck. But it should not be a common issue.
I imagine there are many mounted by the exhaust, mine is. If that were the issue there would be signs of heat damage, your's looks new - in fact i think i have the same one from fleabay. I'll try to check mine when the boss gets back and i can see what happens when you press the brake.
It's probably a manufacturing defect, may be just a piece of swarf where it doesn't belong.
It's probably a manufacturing defect, may be just a piece of swarf where it doesn't belong.
- City
- Redmond
- State
- OR
I have had problems with the aftermarket ones leaking- it took a few before I got a good one. I had my last one mounted up by the master- works well but screws up the factory line routing. I’m going to place the valve on my current build down in the stock position but put a heat shield on it. I don’t think heat caused your issue though. I’m betting on a poor quality valve. The one I got that didn’t leak was from Summit.
- City
- Richmond
- State
- TX
When fixing the brakes on the overlander, I ended up buying an original recycled part. I was never happy with the aftermarket ones and the different switch on it. It turns out, my original was probably just fine as I had a bad flex line in the rear.
On the left- leaking part from A-Team Performance on Amazon. On the right- replacement part from Classic Performance Products on Summit Racing.
notice the replacement doesn’t have that hole that leaked. I thought it was interesting, thought I would share.
- City
- Cave Creek
- State
- AZ
Thanks. My OEM valve is leaking at a trickle. I'll need to replace it sooner rather than later.
- City
- NW Chicago Suburb
- State
- IL
Very interesting observation - much Thanks for sharing. It gives the appearance that the hole in the left unit is an enhancement by design for some unknown reason (especially since it is purposefully designed and subsequent to the OEM design)
Any hydraulic fluid engineers reading this post?
Could it be another unused port for another applicaton?
Could it be a pressure relief port? (which sounds ridiculous on a brake system to this layman, but who knows?)
- City
- Richmond
- State
- TX
I replaced the combo valve on the ‘83 when fixing the brakes. Tried numerous aftermarket ones, but they all had different switches. I think finding a used original in good condition, or if lucky NOS is the best option.
- City
- NW Chicago Suburb
- State
- IL
All - I couldn't stop thinking about this port (pressure relief?) that is obviously designed into the rear brake line adapter.
I ended up finding this YouTube where another guy talks about his experiences with it on a recently installed NEW replacement combination valve (i.e., combination metering & proportioning functionality).
This YouTube is good to watch only from minutes 0-8. After minute 8 he begins talking about converting the combination valve which is not applicable to this CJ-8.com thread.
Interesting:
- lots of owners of other vehicles (S10s and Cameros) have encountered leaking from this port.
- no one has been able to figure out why it is there
- this YouTube host shows what he discovered when tearing-down his recently installed NEW replacement combination valve that started leaking from the port in question (Answer: He found disintegrated rubber O-rings in the recently installed NEW replacement valve -- the O-rings are suspected as not being compatible with brake fluid).
