Fuselage - Drums to Disc Brake Conversion

[70_NPORT]

Alright...back on they go. I didn't notice any "drag" or difficulty in screwing the hoses into the calipers again (with new washers). Each is tightened down pretty good...I can't see how any fluid can possibly get up in the threads and past the washer.

 

[Big_John]

The threads don't seal. They are a straight thread, not like a tapered pipe thread (remember NPT?) where the thread is tightened to the point of interference and the threads seal. A straight thread will have that type of interference fit and will not hold pressure.

The washer is the ONLY thing that seals this.

 

[70_NPORT]

Reinstalled...started bleeding again.....pass side still looks like there is a tiny weep...can't tighten that in any further than what it is.

 

[1970cat]

if you have the used ribbed washers or if someone knows where to find new ones, use them. i have never been able to get the flat ones to seal.

 

[70_NPORT]

I dont know....this is getting ridiculous....the otherside seems to be ok thankfully. I might just leave the other one alone.

 

[traintech55]

If you need practice, go down and pick up a piece of tubing and cut the ends off and have at it. And yes I did refer to the Kelsey Hayes calipers as the Chrysler ones. They are what was engineered for the same size car in later years, and they worked damn good.

 

[Big_John]

I dont know....this is getting ridiculous....the otherside seems to be ok thankfully. I might just leave the other one alone.

I'm not sure which one you want to leave alone.

Don't touch the one that's sealed (obviously). You don't sound sure about the one that is leaking, so spray some brake cleaner on it and make sure it is.

You can't let this go. It's not safe.

Now that it has set for a day or so, I would try giving it another tug with the wrench. The washer is soft copper and now everything has had a chance to stretch/compress etc. It may just need that.

If that doesn't work, you are back to taking it apart and checking the surfaces again and installing another washer.

I've never had an issue with these as long as I was using a new washer, so I'm out of ideas.

 

[70bigblockdodge]

I thought Kelsy-Hayes had inverted flares in the caliper. Front brake hoses is what they used to mount the master cylinders on the 68 A body Hemi cars so you can adjust the rocker arms.

 

[70_NPORT]

It is what it is. I can't wrench on it any further. There's no leaking, but the way this POS has been going that might change in the next two minutes. I gonna wrap it up.

 

[Big_John]

So... there's no brake fluid around the fitting??

 

[tallhair]

It is what it is. I can't wrench on it any further. There's no leaking, but the way this POS has been going that might change in the next two minutes. I gonna wrap it up.

Gary's going oooofff the grid

 

[70_NPORT]

So... there's no brake fluid around the fitting??

One side (pass side) has a sight "weep"; meaning if brake pedal pushed down 10 or 15 times, a tiny amount of fluid congregates at the bottom of the washer. I can't screw it down any further it is at its end.

 

[commando1]

Gary, is the hose fitting bottoming out before the washer is fully compressed?
Shave a hair off the end of the hose fitting.
Or stack two washers.

 

[70_NPORT]

Gary, is the hose fitting bottoming out before the washer is fully compressed?
Shave a hair off the end of the hose fitting.
Or stack two washers.

Wut do you think of them?

 

[Big_John]

One side (pass side) has a sight "weep"; meaning if brake pedal pushed down 10 or 15 times, a tiny amount of fluid congregates at the bottom of the washer. I can't screw it down any further it is at its end.

That's not acceptable. You can't let it go. It has to seal.

As I've said, if you think it's as tight as it should be, then inspect the sealing surfaces and use a new washer. The sealing surfaces (note I did not say threads) on both the caliper and hose have to be clean and smooth. No burrs, scrapes etc.

I'd try for a thicker washer if possible....Stan's idea of a second washer should be good too, although I've never done it or seen it done. Maybe someone else can confirm that as good.

You've come this far, this is just a minor issue that you can overcome.

 

[Big_John]

You can check the depth of the thread in the caliper by screwing the hose down into the caliper with no washer on it.

 

[cantflip]

Your correct... thanks for jogging my brain, when apart use a tooth pic or some thing to measure the depth of the caliper threads and compare that to the hose end... may have a parts mismatch. If the hose threads are too long you might cure this by filing off a tiny amount of material from the hose, a thicker sealing ring could do it too, but yours looked to be pretty thick. Whatever the case, you are very close so your problem is going to be some thing really small. If the threads look to have good depth, just try new rings first.

While fooling around with this that hose will want to drip all of the fluid away... find some rubber caps that fit snug or a small piece of hose and plug the end... it will save you having to bleed an empty master cylinder circuit.

Please read this again. Also, stacked washers might actually seal, but isn't correct... find a thicker washer if you must. The stack potentially could allow the hose to loosen over time and give an unexpected leak down the road (when you turn the wheels the washers wouldn't have bite into each other). The stack would not be able to crush into each other to provide the interference seal you need. I don't know about others here, but I have found that some washers are softer than others... you never really know what the copper content is. Maybe try a different source for your washers if you can't get the ones you're using to work.

On the bright side, you have gotten pretty good at bleeding the brakes by now.

 

[commando1]

Dorman 66223 brake line fitting crush washer.

Available most stores. Get a ½ dz.

 

[70_NPORT]

Dorman 66223 brake line fitting crush washer.

Available most stores. Get a ½ dz.

Yeah I had 2 new spares; I'm on the second pair now.

 

[70_NPORT]

So I was able to get the drivers side to seal up totally dry, however the pass side still has just the slightest barely noticeable tiny "weep" at the bottom of the washer, not enough to even make a drip.....and it only occurs when the brake pedal is pushed down a bunch of times consecutively. Maybe the surface of the caliber is irregular (?) maybe I dunno....I'm sure RA would take it back if I were to tell them that (NOT). Its not worth the hassle....and the brake pedal feels really good btw.

However I can tell by spinning the wheels the pads are dragging on the rotors. The brake pedal piston that rides inside the MC - the length needs to be adjusted.