The vacuum issue...

[Fightfan]

While I am in the middle of my "6.2L into a YJ" situation, I am going over my vacuum issue. I plan on leaving my brake system intact and using a vacuum pump. I found on from Stainless Steel Brakes that is specifically used for this. Has anyone else done this or used a different method? I am not even remotely interested in changing an entire brake system if I need something as simple as a vacuum pump to solve my situation.

[HH]

Installing a hydro boost system is not hard. I used a set up from a van, see Grand Cherokee in my sig. They were used on gas and diesel engines. The lines should fit as the YJ box is same/similar as used by GM.

[Fightfan]

HH,
I recieved an email back from SSBC and they said their pump set up is designed for race cars that don't have much vacuum. I can get the pump for less than $300.00 and have it installed in less time than it would take to monkey around with the hydro boost. Plus, it comes with a warranty. With the Dana 44's that are going under my jeep, I will have disc brakes front and rear. I would prefer the vacuum pump over hydro boost for this.

[4xjunkie]

Has anyone else done this or used a different method? I

Yes. My Ford F350 uses a vacuum pump on the diesel for the brakes.Works great.

I plan on using a vacuum pump in my YJ.

If the cam driven pump doesn't do it, you might have to go belt driven.

[Fightfan]

Before I go any further, I would like to apologise to HH if it seemed like I was trying to slam him with his suggestion. Totally not the case. I am fishing for advice and I cetainly appreciate any help I can get, especially since I asked for it. Going back to this vacuum pump, I am open to suggestions. Since my Jeep will be used in all kinds of conditions, (on/off road, snow, etc.) I am looking for the best braking capability possible with the least amount of complication or opportunity for failure. The vacuum pump could fail (hopefully under warranty), but with a hydro boost failure I would lose power steering and brakes. This would be especially catastrophic 10 miles in the backwoods.

[convert2diesel]

When I first got my conversion on the road, I was using the stock vacuum pump with the original braking system that came with the Buick. This worked but the problem was rise time. Took about a three count to recover. This created problems especially at intersections when you had to come onto the brakes a couple of times in a row.

Tried a couple of resevoirs but that still didn't fully correct the problem so I re-worked a suspension compressor (auto level) to suck not blow and installed a vacuum switch that turned on at 8 inches and turned off at 18. This worked well but the constant buzz of the compressor/vacuum pump drove me nuts, especially sitting in traffic with your foot on the brakes. Apparently Ford used this set-up on some of their trucks but have not been able to come up with a part number (or for that matter what trucks used the electric pump) for the supplemental vacuum pump. A number of 80s GM cars (the big ones with the V6) used an electric pump so you might find one in the yards.

Eventually went with the hydro-boost but am not very happy with the results. Had to change the master to fit the unit and am not sure the valving is the same. The vacuuum brakes worked much better.

When I get around to the Cadillac conversion I am going to revisit the vacuum option. Maybe mount the compressor to the chassis and build a sound proof enclosure.

Bill