Inline Proportion Valve has flare port in place of bleeder.

[PbFut]

New proportioning valve from Inline Tube has an inverted flare port in place of a bleeder port. What have others done to get a bleeder at this location? I’ve been looping round and round with both inline and local parts stores looking for a solution. A local hydraulic line shop can cobble up a number of fittings but it looks ridiculous when complete. Short of finding a correctly ported valve body, which is likely another 100 bucks from a different vender, anyone know of a flare port to bleeder adaptor? Using a port plug and cracking it to bleed is an option but you can’t get the air out of the hollow section of the plug in the orientation it sits. My last option is to JB Weld the space in the plug eliminating most of the air gap and dealing with the very small amount of air that would remain. Because of the angled upright orientation relative to the path the air would take to exit past the plug threads it would not be a perfect bleed but likely acceptable. Thoughts?

[LNP]

Cant say out of all my years in the garage I've seen a proportioning valve with a bleeder screw. You should have 6 holes in it a few have 4 or 5. But most have 6. 1) rear brake line, 2) master cylinder lines, 2) frt brake lines, and 1) for the brake light switch. Post a photo of yours

[PbFut]

Correct 6 holes. 2 MC, 2 for F & R Brake Circuit, 1 for sensor, 1 for bleeder. Original to the 72 GMC C20 the valve block on left. Front port just above the reset button is machined for a bleeder on the original part. The same port on the new block is a inverted flare port. Fine if you need for a remote bleeder but getting an adapter for this port for a normal bleeder has been a challenge.

[HO455]

I don't see JB Weld as a solution due to the pressure involved. Brake line pressure can easily get to 1200 psi and above. Plus I believe JB Weld is going to break down when exposed to brake fluid over time.
So as I see it you can...
One, use a inverted flare plug (see link and photo) and try to bleed the plug as best as possible
.
Two, have a local person with a lathe make you a custom fitting with a bleeder in it.

Three, have your old valve rebuilt. I believe there is a member here who does them.

https://www.summitracing.com/parts/e...yABEgJsbPD_BwE

[LNP]

Originally Posted by PbFut

Correct 6 holes. 2 MC, 2 for F & R Brake Circuit, 1 for sensor, 1 for bleeder. Original to the 72 GMC C20 the valve block on left. Front port just above the reset button is machined for a bleeder on the original part. The same port on the new block is a inverted flare port. Fine if you need for a remote bleeder but getting an adapter for this port for a normal bleeder has been a challenge.

No thats a frt brake line port. If they have a bleeder in a proportioning valve I have never seen one so I wont argue beyond my 30 plus years workin in a garage. But doesnt mean I know everything or have seen everything. But what I do know is that new valve you have does not have a port for a bleeder. It does look like a bleeder hole in your old one although it is hard to tell for sure. Now you may be able to rig something up. I'm not gunna say how it would work.

[LNP]

I did look and I find they did have one in the early 70's with a bleeder screw but I cant find anyone that makes them today so far. Here they have them pictured in the discussion

http://67-72chevytrucks.com/vboard/s...d.php?t=781209

[LNP]

This fitting may help you out.

https://www.napaonline.com/en/p/UP_B...&gclsrc=aw.ds&

[Tditch]

I had the same issue when I upgrade my valve and I really struggled to find the right fitting. My solution was to get a anodized flare plug and carefully drill it out to be an inverted flare fitting. I also added an o-ring to it, to help create a secondary seal to the valve. I've been driving it for over a year now with no issues.

[PbFut]

I am 100% sure the port in question on the old valve is a bleeder port. I have the bleeder nipple on the workbench and there is no inverted flare in the hole of the original block.
I find it interesting that these "new" valve blocks have this additional flare port in a upwards prone position and nobody has complained. All the plugs I am aware of have a void past the machined flare surface presumably as part of the manufacturing process. This void in the plug will be oriented in a way that an air bubble will be present and not bleedable. A flare in this port is almost worthless. If one wanted a external bleeder or pressure gauge a correct bleeder port can be used, but not the other way around without a pile of linked adapters. What's everyone doing with this port? Stuffing a plug in it and wondering why they cant get a firm brake pedal?

[Sheepdip]

I plugged mine with the inverted flare plug that HO455 posted, if you want to bleed it just crack it open, bleed it, then cinch it back down.

[PbFut]

Originally Posted by Sheepdip

I plugged mine with the inverted flare plug that HO455 posted, if you want to bleed it just crack it open, bleed it, then cinch it back down.

This method will leave a bubble in the body of the plug.
I took a photo but the camera does not pick up depth very well.
One plug is filled with epoxy.
It is a .190 hole and about .325 deep. A bubble that size cannot be purged when the path for escape is inverted.
The plug has a space that will trap air in an inverted position which will be impossible to bleed completely. It is small but will be present. Though you don't have to get 100% of the air out of a brake system to work, the pedal feel is improved by purging anything possible. Knowingly having a bubble in a the proportion valve is just against my nature.
My solution at this point is to fill the plug using JB Weld to just below were the inverted flare in the port will contact the plug. This should allow for a good seal when tighten down. I can crack open the plug and try to bleed any remaining air and will not have to worry about the bubble deeper in the plug. There is a risk of reaction of the epoxy with the fluid. I will have to keep an eye on it for a while. Brake fluid does not seem to effect my epoxy floor so I am hopeful. At least I won't obsess over a damn bubble in the valve.

[RichardJ]

>>At least I won't obsess over a damn bubble in the valve<<

But, in fact you are.

Thousands have used a plug like that and not had a problem bleeding the lines.
Find a plug that isn't hollow.
Use a brass plug and solder the hole closed.
Drop a ball bearing in the hole before you put the plug in.

There will be several high spots in any brake system and the fluid will carry the air bubbles with it as you push the fluid through while bleeding.

Incidentally, that isn't a "reset button". It's a Metering Valve.

[HO455]

Originally Posted by PbFut

This method will leave a bubble in the body of the plug.
I took a photo but the camera does not pick up depth very well.
One plug is filled with epoxy.
It is a .190 hole and about .325 deep. A bubble that size cannot be purged when the path for escape is inverted.
The plug has a space that will trap air in an inverted position which will be impossible to bleed completely. It is small but will be present. Though you don't have to get 100% of the air out of a brake system to work, the pedal feel is improved by purging anything possible. Knowingly having a bubble in a the proportion valve is just against my nature.
My solution at this point is to fill the plug using JB Weld to just below were the inverted flare in the port will contact the plug. This should allow for a good seal when tighten down. I can crack open the plug and try to bleed any remaining air and will not have to worry about the bubble deeper in the plug. There is a risk of reaction of the epoxy with the fluid. I will have to keep an eye on it for a while. Brake fluid does not seem to effect my epoxy floor so I am hopeful. At least I won't obsess over a damn bubble in the valve.

You could tap the void space in the plug and thread a stud into it.

[Tom1878]

Advance Auto has inverted flare plugs to fit it, that's what I did with mine. I believe the part# is BLF-60C, it's 3/8-24 if I remember correctly.