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Brake lines - 9 bolt PBR disc to 10 bolt drum

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Old 12-05-2018, 02:08 PM
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Brake lines - 9 bolt PBR disc to 10 bolt drum

So my 9 bolt is gettin a little old, and I got a great deal on a 10 bolt drum with a 3.42 Torsen diff already installed. Picked up some mounting brackets from Ed miller, and am hoping to do the swap soon. The 10 bolt does NOT have brake lines. I had planned on swapping over all the lines from the 9 bolt. Parking brake cables too. SOOOO much info via search it was hard to sort though. Anyone have any thoughts on this?
Old 12-05-2018, 02:31 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

If both are drums and they both use the same slave cylinder (or atleast the same size fitting) you should be able to move the brake lines over, may need to do a little bending and tweaking. Possibly tack on some new clips but shouldn't be too much effort. Not sure on the parking brake cables. Maybe look on something like rock auto and see if they list different part numbers between the 9 bolt car and the 10 bolt car.

The flares on the rear brake lines are pretty simple so if they don't work you could borrow a flair tool and buy some straight line. I would suggest getting new rubber hose (or braided line) to replace the soft line between the body hard line and the hard line on the axle. This and the soft lines on the front make for a softer pedal.
Old 12-05-2018, 02:39 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

I have a 9 bolt PBR disc. I'm swapping those brakes over to my new 10 bolt drum rear. I have the brackets for the calipers. Is there any reason that I can't use my existing brakelines? Essentially the ENTIRE braking system will remain unchanged. I don't see why there would be an issue, I just figured I'd ask.
Old 12-05-2018, 03:04 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

Should be good as long as the brake end brackets will mount to the 10 bolt, I don't recall. Your only issue might be a slight width difference but you should have enough flex in the lines.

You might when be able to unclip the lines from the existing axle and zip tie your calipers to the car and not even open the brakes. Drop the axle and put in new one and reinstall the brakes.
Old 12-05-2018, 03:17 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

You might when be able to unclip the lines from the existing axle and zip tie your calipers to the car and not even open the brakes. Drop the axle and put in new one and reinstall the brakes.
LOL....I actually am considering that! ....but a full four corner bleed hasn't been done in a long time. Probably use this as an excuse to go through it all.
Old 12-05-2018, 03:55 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

Originally Posted by Abubaca
I have a 9 bolt PBR disc. I'm swapping those brakes over to my new 10 bolt drum rear. I have the brackets for the calipers. Is there any reason that I can't use my existing brakelines?
The 9-bolt will have the calipers clocked to the rear and both hard lines end with a flex line. How that will impact drums, I'm unsure.

JamesC
Old 12-05-2018, 07:17 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

I apologize as I have clearly misrepresented my goal. I currently HAVE PBR discs, and I'm swapping them over to the 10 bolt. Calipers, lines, rotors, pads and all. The only reason I mention that the 10 bolt has (had) drums was in the event that somehow the drum rear housing was different than the disc rear, and it somehow affected the lines. I don't see HOW it would matter, but stranger things have happened in the world of thirdgens.
Old 12-05-2018, 07:34 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

If the brake lines don't just swap right over, it shouldn't be too difficult to tweak them, or bend straight lengths from the parts store. Reproductions are available too, IIRC. I'd throw up a picture of the 10-bolt PBR lines, but mine are in the attic with a vaguely Firebird shaped modern art master-piece parked under the attic ladder...
Old 12-05-2018, 08:15 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

I figured it may take a little schmoozing, but should be fairly straight forward.
Old 12-05-2018, 09:09 PM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

Originally Posted by Abubaca
I figured it may take a little schmoozing, but should be fairly straight forward.
The 9- and 10-bolt PBR braking systems are identical. I used 9-bolt lines when I converted to PBRs on my 10-bolt.

JamesC
Old 12-06-2018, 07:02 AM
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Re: Brake lines - 9 bolt PBR disc to 10 bolt drum

The 9- and 10-bolt PBR braking systems are identical. I used 9-bolt lines when I converted to PBRs on my 10-bolt.
AWESOME! ...that's what I was hoping for. Thank you, and sorry for the confusion.
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