Brake line tightening down

[CopperBronco]

I’m in the final stages of my hydroboost install. This is a dumb question probably, but doing full hard braking tests at idle to test for leaks.

Every time I panic stop test I get the smallest amount of residual brake fluid coming out. I’ll tighten/loosen/tighten/loosen and get it down a bit more. It will stop leaking, then do another panic test and it will leak somewhere else…

I’m only using a handheld 3/8 flare nut wrench and a brake bleeder wrench… the caliper threads tend to seep a little fluid each time I panic test, and different fittings up at master cylinder.

Wilwood told me no thread sealant, no Teflon tape, no thing, just metal to metal contact… I already cross threaded/stripped my prop valve earlier this week and had to redo.

Are there specific torque values for all these somehow? Or another way to know if too tight or too loose? Video examples are welcome as well.

Thanks in advance!

 

[gnpenning]

You mentioned a couple areas for leaks. Be aware of the places that have copper washers. If the washer is to hard you will have trouble getting it to seal.

Check the sealing surfaces for pitting especially if they are rebuilt.

 

[Slowleak]

I would not use any thread sealant or tape. The sealing surface is the flare itself. Give Wilwood a call……

 

[CopperBronco]

I would not use any thread sealant or tape. The sealing surface is the flare itself. Give Wilwood a call……

Yep! I played leak whac-a-mole just tightening / loosening carefully… took over an hour as I tested and tightened multiple times… but finally got 3 hard panic stops in a row and then no leaks or wetness around threads… now for a slow speed drive test and check again in AM.

 

[Wild horse 75]

Flare fittings seal on the taper. Make sure the lines and seat are clean. If everything is brand new it’s not uncommon to need to tighten and loosen them a few times just to get them to wear into each other. Also they need to be tight. Like not just tight but TIGHT. You need to deform the metal slightly to make it seal. NPT fittings on the calliper should have some sealant on them as you don’t want to gall the threads and contrary to popular belief Teflon is a lubricant not sealant. NPT actually needs the lubricant to allow it to seat down further so it seals. Flare fittings don’t need that. I usually use some neverseize on the threads and under the nut for preventative measures down the road but only a little. All your leak testing should be done in the garage not the road. Cause a small split in a line could be a very bad thing on the road. If it doesn’t leak in the garage it shouldn’t leak on the road.

 

[CopperBronco]

One last issue, brake lights won’t come on… but if I go down and press on spring on the brake light pedal switch they do, so wiring is fine… did I hook this up wrong?

 

[gr8scott]

Same thing happened to me some time ago. The top plate where the brake pedal makes contact with the switch looks bent. I glued a small piece of sheet metal to that plate and it's been good ever since.

 

[CopperBronco]

Same thing happened to me some time ago. The top plate where the brake pedal makes contact with the switch looks bent. I glued a small piece of sheet metal to that plate and it's been good ever since.

View attachment 906762

I’ll take a closer look, you have a photo of this? And why would that work? Am I covering the hole there with sheet metal? And then it’s connecting it somehow to complete the circuit?

 

[gr8scott]

I’ll take a closer look, you have a photo of this? And why would that work? Am I covering the hole there with sheet metal? And then it’s connecting it somehow to complete the circuit?

Your brake lights aren't working because the top plate of the brake light switch is bent. Because it's bent, it wont go down far enough to complete the circuit to turn on your brake lights. Gluing something to the center of that plate just makes up for it being bent, so that it will go down far enough to complete the circuit.
Like I said, all I used was a small piece of sheet metal.

 

[Steve83]

Video examples are welcome as well.

Videos aren't necessary, but good clear still pics of YOURS would help us help you.

Because it's bent, it wont go down far enough to complete the circuit to turn on your brake lights.

That's not how that switch works - the plate is just a bearing to allow the booster pushrod eye to move if necessary. The bend doesn't prevent it from working since it's only the center that matters. The actual problem is that the eye wall isn't thick enough to press the switch (possibly due to wear, or poor manufacturing, or debris inside the eye around the pedal pin). Your metal shim made up for the gap.

 

[B RON CO]

Hi, I haven't been following the whole brake upgrade, but if you are using stainless line it could be hard to get the flares to seal because stainless is harder than regular brake line. The softer line squeezes to conform together easier. As mentioned, you can check, replace, clean, or flip over the copper washers on the caliper lines. I usually reuse the copper washers with no problem. You can check the brake light switch with a test light. One wire is the hot feed, and the other wire should go hot when you push down on the pedal. I would get a quality replacement switch from Napa. Good luck

 

[Brush Hog]

Try rotating brake switch end for end 180 degrees. I had mine in the wrong direction and lights wouldn’t work. Spun it and then no problems.

 

[toddz69]

Where are exactly are you getting leaks? It sounds like it's at the calipers? And if the bleeder screws are leaking, do you have Wilwood calipers?

Todd Z.

 

[CopperBronco]

Where are exactly are you getting leaks? It sounds like it's at the calipers? And if the bleeder screws are leaking, do you have Wilwood calipers?

Todd Z.

Now the only place is front passenger bleeder, they are GM calipers… just weeping barely from the threads… anyone have a torque value for those… debating moving from handheld wrench to a socket wrench but going carefully to see if I can tighten it up, afraid or stripping the threads.

 

[CopperBronco]

Try rotating brake switch end for end 180 degrees. I had mine in the wrong direction and lights wouldn’t work. Spun it and then no problems.

I think it’s on the right way as I took photos of it before I removed it, so matching to the previous position.

 

[CopperBronco]

Videos aren't necessary, but good clear still pics of YOURS would help us help you.

That's not how that switch works - the plate is just a bearing to allow the booster pushrod eye to move if necessary. The bend doesn't prevent it from working since it's only the center that matters. The actual problem is that the eye wall isn't thick enough to press the switch (possibly due to wear, or poor manufacturing, or debris inside the eye around the pedal pin). Your metal shim made up for the gap.

I’d need a diagram with labels to understand what you’re saying… eyewall? Of the booster pushrod isn’t thick enough? So I’d need to essentially “shim/extend” to make it work? Or are you referring to the switch itself? Sorry, never done this before.

 

[CopperBronco]

Here are more photos, also the bleeder screw is still leaking… going to replace. My bleeder screws fit a 10mm wrench… do I need the M10x1.5 size? Looking at Dorman part# 12702. I have the GM brake conversion… didn’t do the install… so double checking GM brakes are Metric… worried I’ve already overtightened as it sounds like torque for bleeders isn’t much more than 8-12 ft/lb on most vehicles…

 

[Oldtimer]

Eyewall. . .

 

[CopperBronco]

This makes sense, I tried a small shim, very thin… maybe a 1/16”… or less. Just made brake lights come on all the time… I’m assuming the tolerance here are sensitive?

 

[DirtDonk]

All this talk about fiddling with the switch is good, but sometimes they simply wear out and don’t work.
This is one of the components that we don’t hear many complaints about when people buy new parts. They usually work.
I know modern parts are a crapshoot, and maybe these don’t get replaced often enough to become an issue. But maybe it’s just time to get a new one.