Cadillac Owners Forum banner

1 - 20 of 106 Posts

·
Registered
Joined
·
7,237 Posts
Discussion Starter #1
Fleetwood Rear Disc Conversion Kit

Is anyone here, besides me, interested in a rear disc conversion 'kit' for their '93-'96 Fleetwood?

There's someone on the Impalla forum putting all the parts numbers together,having a part custom made and including an instruction sheet in order to make the coversion much easier.

This kit will inable you to convert the rear drum of the Fleetwood to the rear discs of the Impalla SS.

Send me your e-mail if interested.
 

·
Registered
Joined
·
7,658 Posts
Re: Fleetwood Rear Disc Conversion Kit

It'd definitely have to be easier to change the pads........
 

·
Registered
Joined
·
7,237 Posts
Discussion Starter #4
Re: Fleetwood Rear Disc Conversion Kit

Sal Collaziano said:
Let's discuss the benefits of a conversion.. This can actually become a pretty educational thread... How much do you think it would cost?
Here's the PM I received.

I can get disc brake backing plates--for both sides. The addition of disc brakes to the Fleetwood rear, while maintaining 4-channel ABS functionality, is doable.

What I propose is putting together a package that will consist of the modified disc brake backing plates, a park brake kit, a set of instructions, and a parts list.

The parts list will contain all the items you will need to complete the installation of the stock Impala SS/9C1 rear disc brakes--rotors, calipers, caliper brackets, pads, park brake cables, brake hoses (at each caliper), fittings, hardware, etc. I do not yet know what the cost of the parts I provide will be, or what the cost of the rest of the items will be--some of you may have access to used parts, but I honestly will say that if you go with all new parts, and you buy a little at a time, if budget is an issue, the total cost is probably not going to exceed $600, but that is just a guess.

One item remains to be resolved--new hard brake lines are needed for the rear axle housing. I want to get Classic Tube (in NY) to bend up these parts in a quantity--if I buy a few sets and each of you buys one, they'll do it at a decent price, and they'll make them in stainless material with the correct fittings. The Fleetwood is unique as far as these lines, and I've asked Kelly Rosato to see if he can find some of the lines. If any of you have access to a 93 or later FW and can either make these lines available, or make a copy of the shapes with coat hangers or some other stiff wire, it will help Classic--they already make a set of these lines for the Impala/9C1, so the outboard end shape is already set, and all that is really needed is the shape from the connections at the top of the diff housing down to each axle tube. If you are really determined to do it on your own, good luck, as the fittings are very hard to find--unless you cut up your existing lines to re-use the fittings. I'd really suggest we let Classic Tube do this. About $40 in stainless.

The tread width is not affected by this conversion, in case there was that concern, and it has been reported that this disc/caliper setup clears factory 15" steel and aluminum wheels.

If you have or can access some used disc brake backing plates, I can modify those, or will take them in exchange, so the cost of modified plates is only the actual machining charge..

The one thing I know little about is the ABS plumbing at the front of the car, and how the proportioning system works on this car. Since there are 2 lines running from the ABS unit to the rear--1 to each wheel--are there 2 proportioning valves, or just 1? I can look this up in my parts fiche, and will report--would be interesting if the prop valve is the same as on the Chevys, since that would allow you to also implement the combination valve modification ("stealth bolt" as its more commonly called--incorrectly--now) to increase the rear brake force.

2 things that you should know--the ABS sensor is repositioned from its present location at the bottom side of the drum brake backing plate. For clearance, a small amount of grinding on the axle housing flange--where the backing plate is bolted on--will be required. Also, it will requre that the 2 rear ABS sensor/cable assemblies get swapped from side to side to maintain proper sensor orientation to the tone ring on each axle shaft. Other than these details, this is a fairly straightforward bolt-on deal.

Like I said, its doable. Now, who REALLY wants to play? I'm ready to work out the details for ordering the backing plates, so if you are IN, let me know ASAP. I need no money at this point. If you know of any others with Fleetwoods I have not listed here, please give them a heads-up. I'm not intentionally keeping this off Forum, it just seemed easier to go direct rather than wait for you to pick this out of all the posts that constantly turn over on Forum.
 

·
Registered
Joined
·
6,471 Posts
Re: Fleetwood Rear Disc Conversion Kit

You talked to Bill? Or did you just see the post?
He emailed me today about the "kit" and I was gonna post something here tonight but since you beat me to it.......
Anyway, I can only say that Bill is a very smart guy and I would definately give him the benefit of the doubt on this issue for sure. I say that because I've not ACTUALLY seen his stuff but have followed his progress for a while on this matter. This is NOT something some dude just threw together one weekend, he's been working and problem-solving on this project for quite a while. So I'm inclined to say that if he says he's GOT IT, he does. If and when I personally review his kit, I'll let you know but for now, anyone interested can email Bill direct at: [email protected]
 

·
Registered
Joined
·
754 Posts
Re: Fleetwood Rear Disc Conversion Kit

The only concern I really have is how effective they would really be. It is a common fix to modify the proportioning valve on the Impala to get more (correct) braking bias to the rear discs.

The other thing that haunts me about this is how Caddy has a few different types of heavy duty braking systems for the Fleetwood, getting bigger as the car goes from standard to trailering to livery. ALL DRUMS.

I know GM is not famous for common sense or logic, but the disc setups were already available from the Impala at assembly time. Why didn't they install them then???

That said... I'll probably go ahead and convert mine just because they will look cooler ;)
 

·
Registered
Joined
·
7,237 Posts
Discussion Starter #9
Re: Fleetwood Rear Disc Conversion Kit

ssstealth said:
I know GM is not famous for common sense or logic, but the disc setups were already available from the Impala at assembly time. Why didn't they install them then???
I thought I read somewhere that the Fleetwood has a truck rear axle. Or at least the livery version did or it had truck brakes or something like that.
 

·
Registered
Joined
·
6,471 Posts
Re: Fleetwood Rear Disc Conversion Kit

Only the V4U, B9Q had the "truck" axle and they DID NOT offer ABS. The standard rear in the Fleetwood was basically the same as the "B" body cars and could've been fitted with disc brakes. A few years prior, the full-size RWD Caddy DID offer rear disc but it was kind of a disaster. Back in those days, GM had "issues" with their rear disc setups. They offered poor performance and generally drew complaints from customers due to a low spongy-feeling pedal. And don't even get me started on how much trouble they were to work on, let along how expensive they were.
Hey Bill,
Good to see you here. We could use you here more often. In case anyone here is not familiar with MR. Sadler, he's quite the information source on these cars. I would suggest that anyone with some spare time, should check out his site and see what he's dome to his Fleetwood. The guy was the first person I ran into that was doing Fleetwood mods way back.
 

·
Registered
Joined
·
14,607 Posts
Re: Fleetwood Rear Disc Conversion Kit

just a curious question (not doubting anyone's intelligence)

what about diffrent proprtioning valves or diffrent master cyalnders ? isnt the ammount of fluid being pushed around changeing ? i imagine the bias valve mentioned in a earlier post might work but im curious if the SS got diffrent master cylanders or proportioning valves (this could be checked by crossing master pn#s?)

still looking at picking up a 95-96 fleet to tow around the next G20 to and from events so thats why im being nosy
 

·
Registered
Joined
·
7,237 Posts
Discussion Starter #12
Re: Fleetwood Rear Disc Conversion Kit

Stoneage_Caddy said:
just a curious question (not doubting anyone's intelligence)

what about diffrent proprtioning valves or diffrent master cyalnders ? isnt the ammount of fluid being pushed around changeing ? i imagine the bias valve mentioned in a earlier post might work but im curious if the SS got diffrent master cylanders or proportioning valves (this could be checked by crossing master pn#s?)
"Still being unable to communicate on the Cadillac Forums, in response to the question of the Master Cylinder--I'd say the best thing to do is try it first with the existing unit. It IS a different PN than what is used on the JL9 4-wheel disc system. As I previously mentioned, the proportioning valve is the same on both cars from 93-96. A new MC from GM would be about $180, PN 18029971.

Any of you out there who can help with the rear axle hard pipes--pictures or a sample bent to shape?"

- Bill Harper
 

·
Registered
Joined
·
27 Posts
I'm finally able to post!

Thanks to Jeff and Kevin for passing along bits and pieces on my research on this topic in the interim.

Here's a response I also made to a few of you by e-mail, even though the questions this post responds to were raised on this topic thread:

(edited)

Guys,

I'm still lurking over at the Fleetwood section of the CadillacForum, and while I'm waiting to get registered there (just waiting for the e-mail reply) I looked up a couple of things.

First, the rear drums on any 4-channel ABS-equipped Fleetwood are the same size as any 8.5" axle on a Caprice or Roadmaster sedan--11" x 2". Only the Cadillac J55 Limo (no ABS) and wagons (non-Caddy w/ABS) used the 11.15" x 2.75" drums.

Second, the combination valve used on the disc-brake 94-96 Chevys is the same part as that used on all other 94-96 B & D body sedans with drum brakes. GM Parts group 4.690, PN 10223533. What this tells me is that it WILL be possible to implement the combination valve modification (also known as the "stealth bolt" mod) that is used by many Impala SS/9C1 owners with great results.

As far as how the disc brakes will perform compared to the drums, I don't know what to say. The ability to use the modified proportioning with rear discs is definitely a plus, and the "eye appeal" of rear discs for those using "open" wheels, like the Impala SS wheel, is going to make this change worth the effort. The fact that you will no longer need to adjust the rear drums for best performance is another consideration. Easier maintenance (my opinion) with the discs is a plus. The entire system weighs less, overall--every pound helps! The service parts are commonly available, and the entire system was designed for usd on the B-body by PBR in Australia.
<snip>

So, I hope that answers most questions that have come up. At the moment, I've requested some additional photos from some of you, and possibly some hardware samples (brake lines) to complete the research on this conversion.

As was posted early on, if you want to know more, please contact me directly.

Glad to be aboard!

Bill
 

·
Registered
Joined
·
27 Posts
Here's a link to a photo of the Impala SS rear disc brake backing plates, made in Australia for GM by PBR, as they appear uninstalled, and before modification to work with the 4-channel ABS system on the Fleetwood.

Thanks to Andrew Stewart from Kansas City via Impala SS Forum!

http://www.b-body.info/andrew/images/backingplates.jpg

http://www.b-body.info/andrew/images/backingplates2.jpg

I'm also keeping a topic thread up to date on this project over on Impala SS Forum, in the Fleetwood section.

Bill
 

·
Registered
Joined
·
27 Posts
Brackets,

Yes, the backing plate provides the caliper abutment bracket (GM calls it a PLATE) a place to mount, and holds the park brake shoe and actuating mechanism (the lever and boot you can see in my last post make up part of the system).

Here's a number of links to photos to provide some idea of what these parts look like installed:

http://homepage.mac.com/mgarcia1/.Pictures/NavyLifer/Rear Caliper Bracket Pix/IMG0059.JPG

http://homepage.mac.com/mgarcia1/.Pictures/NavyLifer/Rear Caliper Bracket Pix/IMG0061.JPG

http://homepage.mac.com/mgarcia1/.Pictures/NavyLifer/Rear Caliper Bracket Pix/IMG0066.JPG

These 2 pictures are of a wagon conversion, just to show you the relationship of the rotor, caliper, and caliper bracket to the backing plate:

(right side, caliper mounted--stock caliper is aluminum color)

http://members.spinn.net/~contach/brake1.jpg

(left side, showing plate mounted to axle housing and park brake shoe in place)

http://members.spinn.net/~contach/brake2.jpg

This group of pictures shows the C5 Corvette rear brake upgrade I've done on my own car--using the red Z06 calipers. The spacer in front of the rotor is to permit use of high-offset Camaro SS wheels, 17 x 9 size. In one photo you can see how the park brake cable attaches via the cast-in ear on the backing plate. These photos are of the left side of the car.

http://homepage.mac.com/mgarcia1/.Pictures/NavyLifer/Rear C5 Brakes/IMG0030.JPG

http://homepage.mac.com/mgarcia1/.Pictures/NavyLifer/Rear C5 Brakes/IMG0028.JPG

http://homepage.mac.com/mgarcia1/.Pictures/NavyLifer/Rear C5 Brakes/IMG0019.JPG

If you want to be kept up to date on the progress of this project, drop me a direct e-mail to

[email protected]

Bill
 
1 - 20 of 106 Posts
About this Discussion
105 Replies
21 Participants
csbuckn
Top