Brand new wheel cylinder gone bad

[kenn]

I had JUST finished my rear axle on both sides! I had gear oil in the hubs because of too loose axle nuts and deteriorated cork seals. I cleaned up everything, replaced wheel cylinders, adjusted brakes, and bled the brakes. Everything was PEACHY on multiple drives. I went out today to take a spin and my remote reservoir is completely dry and I had it about 1/2" from the top. There is a puddle on the inside of the rim and it isn't gear oil. The bleed screw and banjo are clean and dry so that leaves only one place it can be coming from...

These are brand new Napa wheel cylinders. I'll open it up and see if I got a "Chinese" spring version vs. the tapered. I honestly didn't open it up as I had read great things about the NAPA ones.

 

[DaneGer21]

I had JUST finished my rear axle on both sides! I had gear oil in the hubs because of too loose axle nuts and deteriorated cork seals. I cleaned up everything, replaced wheel cylinders, adjusted brakes, and bled the brakes. Everything was PEACHY on multiple drives. I went out today to take a spin and my remote reservoir is completely dry and I had it about 1/2" from the top. There is a puddle on the inside of the rim and it isn't gear oil. The bleed screw and banjo are clean and dry so that leaves only one place it can be coming from...

These are brand new Napa wheel cylinders. I'll open it up and see if I got a "Chinese" spring version vs. the tapered. I honestly didn't open it up as I had read great things about the NAPA ones.

Bummer; take pictures if needed for the return process!

 

[Gypsyman]

Now days I check every new part regardless of who it came from. Sad that we have to do that. For example...

Bosch now moves their manufacturing from country to country depending on where they get the best pricing and tax incentives. They will literally shutter a plant and fire up in another country. Unfortunately the quality varies wildly from plant to plant.

Cummins is the same way. One part in particular that I remember was their intake air heaters. 3 countries, 3 plants, and 3 completely different parts all with the same parts label. They bolted in correctly but the part itself was a completely different design based on the country of manufacture.

A few months ago I received a brand new A/C Delco MDT master cylinder. On a whim I decided to pull the reservoir off to see if a remote top plate would work. Both of the compensating valves under the reservoir had been crushed buy improper installation at the factory.

I'm old enough to remember new part failures and mis-manufactured parts being quite rare. Over the last few years it feels like it's become almost commonplace regardless of the brand name.

 

[ToddJK]

Now days I check every new part regardless of who it came from. Sad that we have to do that. For example...

Bosch now moves their manufacturing from country to country depending on where they get the best pricing and tax incentives. They will literally shutter a plant and fire up in another country. Unfortunately the quality varies wildly from plant to plant.

Cummins is the same way. One part in particular that I remember was their intake air heaters. 3 countries, 3 plants, and 3 completely different parts all with the same parts label. They bolted in correctly but the part itself was a completely different design based on the country of manufacture.

A few months ago I received a brand new A/C Delco MDT master cylinder. On a whim I decided to pull the reservoir off to see if a remote top plate would work. Both of the compensating valves under the reservoir had been crushed buy improper installation at the factory.

I'm old enough to remember new part failures and mis-manufactured parts being quite rare. Over the last few years it feels like it's become almost commonplace regardless of the brand name.

Sad but true. Us consumers are the quality control/inspector in most cases now with pretty much any thing. While I have only experienced this once or twice with automotive parts, I've built quite a few AR's and quite a few times I would find a safety selector with the detent groove out of spec and confirmed with assembly as well as triggers, hammers, springs, charging handles, bad staking on gas keys, and barrels with machines defects only detected by a bore scope and confirmed with poor accuracy. If you know what to look for, best thing is to inspect it while still at the shop with the clerk or same day it was delivered.

 

[rustystud]

Before you condemn the wheel cylinders check the fittings going into the wheel cylinders. These are supposed to be torqued to 40ft Ibs . Some manuals say 60ft Ibs.
I had this happen to mine years ago. It ended up being the right front rear axle. Tightened the line down really good and no leak. When installing new cylinders using old brake lines you need to make sure there is a new "set" to the brake line. It is a mechanical seal, the steel brake line to the cast iron wheel cylinder.
If there is a wear line on the brake line "flare" you might have to "ream" the brake line to allow it to reseal.
That or really tighten down the brake line to create that new seal.

 

[HDN]

Before you condemn the wheel cylinders check the fittings going into the wheel cylinders. These are supposed to be torqued to 40ft Ibs . Some manuals say 60ft Ibs.

Is there a line torque wrench? Or is it more of a feel thing? When I've done any brake lines I've just tightened them as far as I can with a line wrench.

 

[HDN]

Now days I check every new part regardless of who it came from. Sad that we have to do that. For example...

Bosch now moves their manufacturing from country to country depending on where they get the best pricing and tax incentives. They will literally shutter a plant and fire up in another country. Unfortunately the quality varies wildly from plant to plant.

I just used the same caution with my GM van. People on the Facebook group were swearing by AC Delco, whereas others were saying that the OEM stuff didn't matter anymore as it was just the same quality as anything. In my case it was a distributor cap, which I ended up buying from a "Daily Driver" brand on RockAuto. I checked the contacts for cleanliness and the cap edge for flatness and I was good to go! Other people had received warped distributor caps from AC Delco Makes me wonder what crap is going into new cars that cost $30000!

 

[kenn]

Before you condemn the wheel cylinders check the fittings going into the wheel cylinders. These are supposed to be torqued to 40ft Ibs . Some manuals say 60ft Ibs.
I had this happen to mine years ago. It ended up being the right front rear axle. Tightened the line down really good and no leak. When installing new cylinders using old brake lines you need to make sure there is a new "set" to the brake line. It is a mechanical seal, the steel brake line to the cast iron wheel cylinder.
If there is a wear line on the brake line "flare" you might have to "ream" the brake line to allow it to reseal.
That or really tighten down the brake line to create that new seal.

I climbed under there and checked carefully around the fitting and the bleed screw with a flashlight and it is clean and dry but I'll check that area again to be certain I'm not missing something. Can it leak to the other side of the plate without showing anything on the bleeder side? Either way, I have to pull the cover/axle assembly to replace the ill-fitting washer I got (posted in another thread) and replace it with an OEM one. For the time being I had bent two tabs forward and two tabs rearward to hold it together while hunting for OEM ones given the lower "tabs" were too short to go over the nut.

 

[rustystud]

Is there a line torque wrench? Or is it more of a feel thing? When I've done any brake lines I've just tightened them as far as I can with a line wrench.

They do make a "line" wrench that has provision for a torque wrench, but there pricey. Just use your best judgement.

 

[kenn]

Before you condemn the wheel cylinders check the fittings going into the wheel cylinders. These are supposed to be torqued to 40ft Ibs . Some manuals say 60ft Ibs.
I had this happen to mine years ago. It ended up being the right front rear axle. Tightened the line down really good and no leak. When installing new cylinders using old brake lines you need to make sure there is a new "set" to the brake line. It is a mechanical seal, the steel brake line to the cast iron wheel cylinder.
If there is a wear line on the brake line "flare" you might have to "ream" the brake line to allow it to reseal.
That or really tighten down the brake line to create that new seal.

Update. I pulled the wheel apart and both ends of the wheel cylinder were DRY. I obviously lost a LOT of fluid but the only place I could see it possibly leaking would be right at the bottom of the banjo bolt as it just touches the hole in the backing plate. It could then have seeped between the two parts of the that backing plate which would have to have happened to get it settled to the inside of the wheel cavity. I wiped and cleaned everything AGAIN, put it back together, and tightened the banjo bolt another 1/8 turn or so as it was already very tight. I'll keep an eye on it again and see where it goes. I don't think the leak was the brake line fitting into the bango but I guess anything is possible at this point.

To add insult to injury, a small amount of gear oil had already made it past the outer bearing seal after only half a dozen drives maybe totaling 100 miles at most. The RTV "cork" was sealed up just fine. It was gear oil moving around the outside edge of the aftermarket AKA made in china seal. I cleaned the bearing, re-packed it, and put another aftermarket on. I guess this is going to have to be a regular event...

A short test drive didn't show any more brake fluid so we'll see...

 

[rustystud]

Brake leaks can be a real pain to find sometimes. Especially with new brake fluid, as it is pretty clear looking. Whenever you open a "line" you really need to pay attention for leaks.