Repair leaking proportioning valve

[Legend_master]

Fit like a glove.

[Dr_Snooz]

That is perfect!

[Dr_Snooz]

I dove into mine today and I'm feeling a lot of anger toward Honda right now. They went to extraordinary lengths to keep me from getting into the valve. First the valve is held together with Torx security bolts. Those are like a regular Torx bolt, but with a post in the middle so normal Torx bits won't work.



You have to buy special Torx bits. I happened to have those hanging around, so Honda failed to stop me. Ha! However, as an additional measure, they cut retention slits in the ends of the bolts. That way when you try to unscrew them, they gall in the aluminum housing and are simply joyful fun to get out. Lucky for me they didn't completely destroy the threads (or my bit thankfully), but I can't think of any good reason to design the prop valve this way. Note that I have an older prop valve here that doesn't have the threads slit. That seems to have come about only with the '89 SE-i prop valve that I'm using. I had planned a quick two minute open and shut repair. Now the valve is covered inside and out with filings, so I have to do a complete rebuild. I probably should do that anyway but I'd rather make that decision without duress.

At any rate, if you plan to do this repair, be prepared for Honda's over-exuberance in this area.

[Legend_master]

Had the exact same problem. I had to cut my bolts, and drill 1 hole. I then used long screws, with washers and nuts to assemble back together.

[Megalodong]

I know this an old thread but, I'm hoping to get a response related to the DPCV (dual proprtional control valve). Fluid was leaking through rubber stopper. I watched a video on the O-ring replacement before I started on removal. Yesterday, I replaced the O-ring that fits between the top and bottom section of the DPCV. I used a Danco #17 O-ring, T-30 Tamper-Proof torx bit for the bolts, and cleaned the inside of the valve thoroughly with brake cleaner and reassembled and tightened it correctly but, still leaks through rubber stopper (only).

I read through this post today and it seems that the DPCV on my car is most likely leaking through the piston(s) O-ring. Anyone know the correct size of the piston O-ring. How to remove the piston?

[Dr_Snooz]

I'm not sure that would leak to the outside?

[Megalodong]

I'm not sure that would leak to the outside?

Turns out stupid me didn't replace the piston O-rings like I should have. So, taking it apart tomorrow and installing Danco #83 and Danco #7 O-rings on the psitons. These Danco O-rings are made of Nitrile rubber (buna-N) and are rated as excellent in resiliency to brake fluid (Glycol). Here's a video that show prop valve repair and installation:

https://www.youtube.com/watch?time_c...&v=biDpFt4GQek

[hatchback_wes]

Bump

Sorry for bumping this super old thread but it is relevant rn lol

Ive been trying to find where my brake fluid is leaking from and it looks like it's coming out of the prop/combo valve. How many screws are there to remove? And have you guys opened the valve up completely to see the inside ? I've looked for new ones online and they're priced at $200+! I'd want to avoid that cost haha

[Dr_Snooz]

It's two bolts and the hard line flare nuts to remove it. Real easy, but be sure to use flare wrenches (10 mm) on the hard lines. The metal is very soft and rounds over at the slightest stress. They'll probably round over anyway, but you have to try, right? Disassembling is two more bolts, but they are special security bolts. You'll have to buy a special kit from Harbor Freight or somewhere to get them. l think the orings inside are hard to find, so be ready for that too.

[hatchback_wes]

Thanks man! How did you do on yours? Mine still has the rubber in it with the fluid leaking out, I was just picking at it with a pic and yup, fluid came out some more.

[Dr_Snooz]

It was an utter failure. But mine wasn't leaking at the body. It was leaking at the flare fittings. I replaced it with a Wilwood prop valve, which frankly, has made a miraculous improvement to the whole braking system. I highly, highly recommend it. You'll have to get handy with a flaring tool and tubing bender though.

https://www.3geez.com/forum/classic-...ghlight=hoopty

[hatchback_wes]

It was an utter failure. But mine wasn't leaking at the body. It was leaking at the flare fittings. I replaced it with a Wilwood prop valve, which frankly, has made a miraculous improvement to the whole braking system. I highly, highly recommend it. You'll have to get handy with a flaring tool and tubing bender though.

https://www.3geez.com/forum/classic-...ghlight=hoopty

Seeing your success of replacing the old prop valve with the wilwood prop valve, it looks like you did a great job! Did you have to remove the carpet and all that to get to the lines? You replaced all the brake lines? How much did your project cost?

[Dr_Snooz]

I was able to re-use the lines to the back, but l had to reflare them because they were leaking and their metric bolts wouldn't work with the standard outlets on the valve. l did replace the front lines, but it was fairly easy with the air box and black box removed. If l had it to do over, I'd look into doing it with AN fittings. Double-flares require a lot care to do right, and they eventually fail. l didn't spend much. Just the valve, some tubing, a cheap bender and equally cheap flaring tool. It was an easy Saturday job, which is really saying something for me.

[hatchback_wes]

I was able to re-use the lines to the back, but l had to reflare them because they were leaking and their metric bolts wouldn't work with the standard outlets on the valve. l did replace the front lines, but it was fairly easy with the air box and black box removed. If l had it to do over, I'd look into doing it with AN fittings. Double-flares require a lot care to do right, and they eventually fail. l didn't spend much. Just the valve, some tubing, a cheap bender and equally cheap flaring tool. It was an easy Saturday job, which is really saying something for me.

Yeah for me it isn't leaking anywhere else except from that rubber stop on the valve. I think I'm going to have to get some PB blaster or something and spray the crap out of it then find a flare wrench and take it off. I think it would be a fun little project to rebuild it and clean it altogether lol

[Oldblueaccord]

This is just a guess but if its leaking there I think thats the way it was design to tell you its leaking internally. We havent been able to find any new for our cars in a while.

[hatchback_wes]

This is just a guess but if its leaking there I think thats the way it was design to tell you its leaking internally. We havent been able to find any new for our cars in a while.

Yeah at this point it is a fact. I checked out the guy on youtube with his del Sol too and seems to be the same issue that he fixed. I want to rebuild it and get new O-rings.

[Dr_Snooz]

I promised Old Blue a write up on my Wilwood conversion. I'll try to get that done this week so you can reference that too if you want. When I did the SE-i rear brake swap, I had to use an SE-i prop valve that I salvaged out of the wrecking yard. The flare fittings in the valve were already deformed to match the brake lines in the other car, and they did not jive with my brake lines at all. It seeped constantly, so I had to find another solution.

[hatchback_wes]

Interesting that the valve deformed for the other car even though I would've thought that brake lines are brake lines. A write up would be awesome !

[Dr_Snooz]

Not the valve so much as the flare seat in the valve. Once the hard line beds into the seat the two deform slightly to create the seal. After 30 years, they don't mix and match so well. That's my theory anyway.

Maybe it's just that certain magic that turns everything l touch into fertilizer.

[Dr_Snooz]

Here's the write-up l did on the problem, complete with photos screwed up by stupid Photobucket.

https://www.3geez.com/forum/restorat...ings-suck.html

Single flared fittings like AN line have different problems, but l think they've superior, which is why all the car show guys use them. They're crazy expensive though.

[Oldblueaccord]

Im studying your new link.

Are AN rated for the brake line pressure?

[Dr_Snooz]

Aren't they rated for everything? Summit has a lot of adapters, so l assume so. The military uses them for everything, l think.

[Dr_Snooz]

Here's what I'm talking about, Blue: https://www.hotrod.com/articles/prop...g-brake-lines/

Instead of doing 45-degree double flares, you do 37-degree single flares. You don't want to use those fancy compression adapters for brakes, but what they're doing in the article should work real good. It's a lot less complicated, and I imagine it seals better, based on how little contact area there is on those double-flares.

* l admit I've never done an AN fitting myself.

l might be over-thinking it, but when you're dealing with an old car with limited parts that you drive a lot, you look for ways to make it easier to disassemble, re-assemble and swap out parts. Double flares just don't offer that. l can't see any reason to do AN fittings on, say, your coolant hoses, but they make a lot of sense for flared hard lines.

[hatchback_wes]

Thanks for that! I'll see what I can do, but redoing brake lines and flares seem like a pain and kinda want to avoid if I can

[Dr_Snooz]

And here it is: https://www.3geez.com/forum/suspensi...ml#post1220514