Brake line diagram - SOLVED (2024)

abs pump should be under the drivers seat ( on the rail)

take a look at the rest of the lines also. if needed something like the dorman stainless kit will come with all that. otherwise it would probably be easier to just to make the line. ( i often end up just getting some hard line an reuse the stock fittings if they are any good.)

bigdog9191999 said:

abs pump should be under the drivers seat ( on the rail)

take a look at the rest of the lines also. if needed something like the dorman stainless kit will come with all that. otherwise it would probably be easier to just to make the line. ( i often end up just getting some hard line an reuse the stock fittings if they are any good.)

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I believe the block under the drivers seat is the controller? There is what looks like a pump on the frame rail up front with a single line from the distribution block running to it.

PNW VietVet said:

Post the last 8 digits of your VIN and hopefully @915_Tahoe will see this and help with the part number. But, what @bigdog9191999 said also relates. How are the rest of the lines/hoses.

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I'll post the VIN digits when I get home later this afternoon. The rest of the lines have already been replaced with NiCop. I missed this one because the fault was on the underside of the braided portion.

shegarty said:

I believe the block under the drivers seat is the controller? There is what looks like a pump on the frame rail up front with a single line from the distribution block running to it.

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grab a pic, sounds like either hydroboost or vac assist chamber.

bigdog9191999 said:

grab a pic, sounds like either hydroboost or vac assist chamber.

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Likely a hydroboost chamber then as the truck is equipped with that. I'll post a pic shortly.

shegarty said:

Likely a hydroboost chamber then as the truck is equipped with that. I'll post a pic shortly.

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It's the large cylinder with the nipple on top, also has two wires

shegarty said:

I'll post the VIN digits when I get home later this afternoon. The rest of the lines have already been replaced with NiCop. I missed this one because the fault was on the underside of the braided portion.

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Last 8 ... 4R291535

Looks like this: https://www.rockauto.com/en/moreinfo.php?pk=1416050&cc=1424191&pt=679&jsn=939&jsn=939 ABS Modulator Valve

The other choice does not look the same and if is the other choice you would have a JL4 RPO code. That would mean you have active brake control and would likely have the master cylinder with a spout out the front of it. Mine has all that with the hydro-boost system.

Is your rig a 1/2 ton or 3/4 ton?