SVO M/C and prop valve question

[machm1969]

I'm converting my '84 to disc brakes. I purchased an '84 SVO prop valve off ebay and a SVO aluminum M/C from advanced auto. I examined the prop valve when it arrived and my friend noticed that it had an "x" in the first few numbers indicating an SVO unit, it otherwise looked the same as my stock '84 prop valve. The prop valve came with the metal lines to the M/C still in place, which I thought should make it a direct bolt in affair. When I went to connect the metal lines from the prop valve to the M/C they wouldn't fit. The metal lines from the prop valve to the M/C are the same size (fittings etc) as my '84 ones and the SVO M/C has much smaller female threads. My '84 has a big flare fitting on the rear line (I think 9/16") and the SVO unit looks like 3 or 5/16" Any idea on why the two units don't match?

Thanks,
Matt

[machm1969]

I figured out two things: I'm dyslexic and I apparently don't retain read material well. I thought that I read that an '85 Town car and an SVO mc were the same, turns out they're not and I have a Town Car mc. But on the brighter side, I did get in installed with a couple of adapters and it works well.

Matt

[TWR2003]

I'm converting my '84 to disc brakes.

Do you mean converting to rear dics brakes?

\ My '84 has a big flare fitting on the rear line (I think 9/16") and the SVO unit looks like 3 or 5/16" Any idea on why the two units don't match?

I believe the SVO fittings are metric.

I figured out two things: I'm dyslexic and I apparently don't retain read material well. I thought that I read that an '85 Town car and an SVO mc were the same, turns out they're not and I have a Town Car mc. But on the brighter side, I did get in installed with a couple of adapters and it works well.

Matt

Isnt Town Car MC (1" piston) for front disc/rear drum and SVO MC for 4 wheel discs? So you are using the Town Car MC with 4 wheel disc setup?

T

ps dont worry - dyslexia goes away as you become senile (ask me how I know).

[machm1969]

I think the SVO uses a 1 1/8" inch bore and the TC is 1". I converted to SN95 rear discs and did a gear swap at the same time 3.55 posi. The car brakes alright, but I'm still battling getting all the air out of the front calipers. I will be switching the fronts to '99 PBR's later next month. I'll post pics.
Matt

[86fiveoh]

i have a town car MC for my rear disc swap too havent put it in yet but heard tht was the best one to use for my car (86). i have 10th annv. cobra calipers in the front and 99 gt's for the rear

[qtrracer]

The problem will be hydrulic advantage. Using the SVO M/C (1-1/8" piston) with the SVO rear caliper (a whopping 53mm) and the 73mm SVO front caliper will work pretty well. On ther other hand, using the smallish sn95 rear caliper (38mm) and the twin pistion PBRs up front (even the late Cobras) with the SVO M/C should result in a very hard pedal; may not even get them to lock. On ther other hand, using the Lincoln or other Ford 1" piston M/C with the sn95 rears and and PBR fronts (including the late Cobra) should work pretty well; but if you stay with the SVO front and rear calipers, could result in a very scary soft pedal. One other thing, the SVO proportioning valve is designed for the 53mm rear caliper/73mm front caliper set up. Anything different will result in unexpected outcomes. This is not the time to reinvent the wheel; you need to get the details clearly fixed in your plan before throwing parts at the car.