u-van front brake upgrade, what's required?

[tlc1976]

Since I'm putting Silhouette 15" wheels on my Cruiser, and the brakes are shot, I'm thinking of upgrading to 92+ u-van brakes. If the donor has ABS it won't be utilized.

I know I need the rotors, calipers, knuckles, hubs, and balljoints (some parts better off new of course). I know the existing tie rods and struts bolt up.

Do I need u-van hoses or will my existing ones work? Probably need the u-van master cylinder too?

And the big question, how about the axles? The Cruiser has a 4 speed auto, so would the donor van, but not the same trans of course. Can I use my existing axles, or do I need something different, or do I need to morph the u-van outer joints to my existing axles?

I'll eventually figure this out if needed, but any prior experience on the subject would always be helpful. There are still a handful of u-vans in the semi-local yard, and while I'm at it I'll probably get the stabilizer bar too.

[Keiths1976]

Actually my friend the hubs can stay as a a body the brake lines can also stay as the a body but if your breaking down the brake system replace them with new lines . Your stock axles are fine with your stock hubs in the car you don’t have to change either of them cause u van and a body are the interchangable . Grab the front sway bar and new bushings too should stiffen up your car lean better . What I would replace is a new brake booster from a u van into your wagon with the brakes should firm it up nicely . The outer tie rods an ball joints has to be U van in theory you can take van struts are interchangeable just will raise the high of the front end 1/2-3/4 depends which van u have is the 3.1 or 3.8 engine rear springs are swap able as long as your wagon is a 93 and under . Hope this helps my friend

[Keiths1976]

You want the whole steering knuckle and calibers if it’s easier just pull the strut and knuckle assembly as one f the vans alignment is good from the tires . If u want take the control arms and bailjoint as one unit and inspect the bushings save them

[Keiths1976]

Gm is funny with somethings they make things to be universal in other cars across the board the U van is your wagon cradle except stronger brakes and sway bar so in theory u could roll out the complete u van cradle engine assembly and will bolt straight under your wagon body steering rack etc... But I wouldn’t do that for few reason the extra weight and stress and rust I seen many u vans cradles lrust completely out by the right passenger control arm and few snapped solid front sway bars in the junk yards over the years . Mostly told me design flaw how it happened since I have yet to see a body wagons or sedans completely rust the cradle that bad . I’m just speculating on this but the way the front windshield flows the run off of rain it pools and sits or the ducks are clogged then Add road salt etc . The rear end also has a few tricks too, the hollow rear axle axle bean has a solid steel bar between it . Gm gave the u van a thicker center steel bar to support the actual weight of the van I would say mostly the 95-6 vans cause all the flaws seem to have been corrected . Granted I’m no Gm wizard just explaining what I have seen and know off hand experience the rusty parts. I have seen in New York junk yards in 2005 saw 4 u vans with rusted out cradles cause of failed state inspections . I hope this all helps my friend just another forum friend sharing .

[tlc1976]

That's cool, I didn't realize the hubs were interchangeable. So that makes it much easier.

I had a spare set of outer tie rods for my Celeb. When I rebuilt the front end on my 92 3.8 van they fit great. But I'll look into new tie rods for a U van.

In the past I put a set of Trans Sport strut assys on my 6000 SE wagon, when I had a DIY snowplow on it. It accounted for the extra weight nicely. Without the plow it sat quite high up front. I'd rather leave my stock ride height. The rear sits quite high, I'll probably leave that alone for now.

Good call on the booster. Had not even thought about that.

The cradle on my 92 van was seriously rusted too. Both sides just in front of the control arms rusted through at the bottom and part of the side. I built up the area with 2 pieces of angle iron on each side, that spanned the bottom completely. I had it strong enough where I could jack up the van using a floor jack at those points. I thought it may have been a false sense of security, as the body is plastic and was always advertised to "never rust". But it was the same old story as anything else underneath, and due to the top lasting forever, the bottom probably got neglected more than other vehicles.

The 86 6000 STE rear disc setup is optimized for 14" wheels. From what I hear, the Uplander rear setup needs 16" wheeels. Any rear disc setups optimized for 15" wheels that you know off hand? If not, I will probably engineer up something myself.

[Keiths1976]

I would still use the Ste swap cause the Uplander there isn’t no e brake set up its totally different set up and 16 inch wheel is needed . I have theorized stuff in my journey of car parts and junk yards . I know Cadillac makes rear disk set up on older Seville’s 89-92 but haven’t had the tools to pull the hubs off to see if the brackets are welded or even a set up to our car but they use a 15 inch wheel but the e brake is a different set up from ours . Next junk yard run look for a 87-92 Seville and see how the set up looks and rake the hub off would be my suggestion that’s why I like u pull it can tinker and pull parts see if it works

[Keiths1976]

Send me a pm my friend

[Duke George V]

Van brakes on car:
Must use minimum 15" wheels, will not fit under stock 14s

Need from 92-95 van at yard:
Knuckles
[This means you cannot acquire the parts from a dealer or parts house. It is possible to find them on ebay.]

Need for van, purchased new:
Ball joint
Brake rotor
Brake pad
Brake caliper
Brake lines, rubber
Outer tie rod

Bolt stock hub onto van knuckle

[lemons bob]

You need to be sure you have the JA2 brakes so you have the right bolt pattern for the wheels. I didn't need new brake lines but wouldn't hurt. Luckily all the other parts are pretty cheap, and unless you have changed the hubs recently might not hurt to replace them too especially if you don't know how old they are, just get a replacement for your a-body. Standard master cylinder is fine might even be the same part.

[tlc1976]

I did think about that since it's got wire wheel covers and I can't see the lugs. But as far as I know, 99.9% of wagons came with JA2 brakes. And if for some reason it didn't, I'd upgrade that too. I'll see what condition the hubs are when I get it up in the air.

My Celebrity was a JA1 car. My kid's mom let me pull what I wanted off her JA2 Celeb when the trailing arm separated, before she scrapped it. Considering I put a bunch of parts on it anyway including Z24 steering wheel, rear discs, new front brakes, one new axle, a set of my rally wheels, and new tires. So that was my donor for the JA2 swap, got it for the price of the tires. Luckily I never had a flat, since it wasn't until almost 10 years later that I realized I never put in a matching spare tire.

[86euro]

The van outer tie rods are definitely larger than what was used on the A-body. I've got the van brakes on my '86, along with STE rear discs and I'm still using the stock '86 master cylinder and proportioning. It's actually very well balanced.

[tlc1976]

This weekend I got a set of knuckles from a 96 U-van. Along with the stabilizer bar & hardware. It's definitely the bigger bar.

I did some digging on Rockauto and it appears the knuckles changed quite a bit. For 92 they had bigger brakes but the tie rod was almost the same size as that from the a-body, only a few thousands of an inch difference. Hence why the Celebrity tie rods fit the same in my 92 van. Next year the upgraded the tie rod again, but had the same caliper. Then for 94 they changed the caliper again. I see in all variations, the caliper bore matches the JA2 a-body, so the pedal should act the same, but the larger diameter should stop it a little better.

For the rears, I did some looking and it appears the 05 Venture rear rotor would work well with the STE caliper. Just a tad thinner so the pads will clear. The STE caliper would be positioned for about same diameter increase as the fronts. And the brake assy should only sit 1/8" farther back, so similar as to when the pads wear anyway. So it should clear my 15" wheels. I'd just have to make a special bracket.

I always used a stock 1987+ JA2 sedan master cylinder with my JA2 front/rear disc a-bodies and I think it balances well.

[86euro]

My front brake setup all came from a '95. I never cross referenced the calipers, but they look similar to what would be found on a similar year Bonneville or Camaro (and others).

[Duke George V]

My front brake setup all came from a '95. I never cross referenced the calipers, but they look similar to what would be found on a similar year Bonneville or Camaro (and others).

Theoretically you could then step up to 93-97 F-body V8 calipers if you get the brackets, and use 00-05 Impala rotors. Minimum wheel size then becomes 16".

[86euro]

Theoretically you could then step up to 93-97 F-body V8 calipers if you get the brackets, and use 00-05 Impala rotors. Minimum wheel size then becomes 16".

I'll have to look into that. I think it's a different knuckle casting though to accommodate the caliper.

In all honesty though, I think the van brakes are about as powerful as you can use before tires become the limiting factor. With coilovers and perfect backspacing, a 245 tire is about the limit. Beyond that, the wheelhousing just plain gets in the way everywhere.