Here is the deal. I am in the middle of a brake swap, using the complete ABS brake system from a 2002 camaro/firebird.

The Reatta uses a porportioning valve with its ABS system. The Camaro does its portportioning throught the ABS valve body.

Would keeping the Reatta valve cause a very spongy pedal?

Daniel, if you're going to use one brake line to feed the rear brakes, I would leave the proportioning valve in the system. It directs equal pressure to both rear brakes. If you're adding the second brake line, the master cylinder will take care of it. Second, with all the work you've done, replace the proportioning valve with a new one. I recently replaced my brake lines & hoses. The proportioning valve was a solid piece of rust. Once I removed it, I could see debis & rust inside all three ports.( Still available through GM--part #25525844--approx: $48.00 ). Hope this helps.

I was under the impression that hte proportioning valve was the most expensive part of the system. There is a "pulling symptom" outlinned in a TSB where GM dictates replacing the proportioning valve for 1990 models and the part is big bucks...1000 - 1400.00 or something outrageous like that??????

I was under the assumption that Daniel was talking about the Rear Proportioning valve, next to the left rear brake hose. This valve is for the rear brakes only. One brake line from the master cylinder feeding both rear brake assemblies.

Nic, you are absolutely correct about the proportioning valve assembly ( valve block assembly ). It is actually a main part of the Teves unit itself.

Hey,Daniel you out there?

If you have too much proportioning, which is what you will have if you employ both valves, the rear brakes will be weaker than they should be, which might cause the fronts to lock, wreaking confusion on your transplanted ABS. But if the transplanted ABS works off of some kind of differential sensor, which it should, it might compensate for the 2 pounds of rust known as the Reatta prop valve. I would try it. You can always replace the valve with a T if something is not right.

Well unfortunately it was not the porportioning vavle. I am almost at a loss here. The only thing that is not new are the rear calipiers. I am not one to replace parts but it is almost my last shot.

The down side is that there is not any sign of failing in either calipier.

Daniel, It seems you may be overlooking the basics of a brake system. There are two things that normally will be the cause of a spongy pedal.

1. Air in the system. Since this is a custom installation you may have a place in a line where air is trapped like a hose or steel line that turns up for a few inches and the goes down again. Brake lines must always keep fluid flowing downwards to prevent air being trapped. You cannot go down, then up and then back down. Air will be trapped at the top. You also could have air trapped in the ABS valves that needs to be purged.

2. Something mechanically is flexing. Could be a hose swelling or a metal part that is supposed to be rigidly held in place is moving. If for some reason the caliper is not able to slide as it normally does while clamping the rotor, the piston will push back on the mounting bracket and cause it to flex.

I would put my money on air being trapped in the system some where.

I dont know if this will help but years ago i bought a 84 camaro could not get the front brakes to work properly after changing everything except rubber lines I undid lines at callipers had someone push on brakes and seen that both the rubber lines were cloged or pinched. just a thought before you buy new callipers.

Daniel, what all was involved in this changeover? Did you have to modify the brake pedal? Cut any brake lines? Can you give us a little summary. If you are dealing with a spongy pedal, seems like you are way past the midpoint of this conversion. I would assume you are getting enough push rod travel to fully actuate the Camaro system.

Chevy makes a good system that works well. Everyone has their own preference on proportioning, so I suggest you use an adjustable proprotioning valve. They aren't too expensive:
Summit Brake Proportioning Valve, Knob Adjustment, 1/8" NPT, Single Inlet/Outlet, Aluminum, Each $38.95
Here's the link: Summit - Proportioning Valves

Spongy pedal can be caused by air, 3-hoses, power booster, or silicone brake fluid, and a combination of all. Each 'zone' can be isolated by blocking off with a plug. If you cannot get all the air out, use vacuum - nothing needs to be removed, and it is absolute (just like the factory). Otherwise, regular bleeding should do it.

I also misunderstood how far you are along. The spongy pedal is probably due to a pocket of air close to the m/c that won't escape by the normal bleeding method. The easiest way to get it out is gravity bleeding a whole quart of brake fluid through the system. You can do all four wheels at the same time but the best way is a wheel at a time so that you can watch for bubbles rising in a section of clear tubing suspended from a strut. But before you do that you must bleed the m/c by loosening one line at a time (at the m/c) while someone pushes the pedal. Get tubing that fits tight on the bleeder valve so you can empty the extracted fluid into a container without making a mess. Steak

Daniel, I would like to know the outcome of your spongy brake problem. What was the problem?

I am not sure as of yet. I have it narrowed down to the rear portion of the system. Also it is not the calipers. I am at a loss. I may switch to the non ABS system from the Eldarodo/Riv.

If you've "settled" for a non-ABS system, why don't you just connect the lines straight to the m/c? (Assuming it has a separate ABS). If you plan on scrapping the Camaro unit for another, Crazytrain2 says that his '89 Park Avenue has a Teves but some came with non-ABS and could be the direct replacement some have been looking for. Also, if you have isolated the source of spongeyness, I would try to find it. It might still be there with the new unit. Steak

Sometime over the next few days I'm replacing the Hydraulic valve assembly on my Teves Mark II system... I have similar brake sponginess issues and I'll let you know if this solves it.

I'll get the bolt pattern from my Teves system and the distance to cotter pin length (+- adjustment)for brake pedal connection to help determine if the swap out system can be used for your Reatta

OK I am going in a bit of a diffrent direction now, and ditching the camaro ABS. I am going to use a 91' riv abs unit. I will try to post a complete write up after it is all working.

try pinching off the rear brake line(s) at the flex hoses and see if the pedal is a lot better, you may need a resudual valve which will keep about 2lbs of pressure in the rear lines at all times

Sorry it didn't work out. 7654321 has done the '91 conversion. But he didn't use the ABS. I suggest you do the same. Steak

I have all the stuff to do the non ABS convertion, but the main point of my endevor is to provide a ABS replacement for those who find they no longer want the Teeves system. I was hoping to use one a bit more common than the 91' ABS system, but the communitcations proved to be more of an issue than the average back yard mechanic would be capable of dealing with.

The issue with using the camaro ABS is I can not make it open the valves to release the air for bleeding. At least that is my best gues of why it is giving me issues. I will know for sure as soon as I install the 91' set up.

Daniel, Before you give up on the Camero ABS read this page. Scroll toward the center of the page to see the procedure for bleeding the ABS.

I have the factory service manual and the Bosch manual for the system, and the bleeding is exactly the same. The issue I have is there is no can2 buss in the Reatta. So there is no way to comunicate with the ABS brain. This also means that the ABS light would be on due to lack of communication with the buss. If I had the tech tool I could figure out a communication set up for it, but no one in there right mind will let me play with a bundle of wires and there tech tool.

I appreciate you trying to come up with a good replacement for the Teves system. I'm sure you will find something that we all can use as a replacement if you keep trying. If I can help, let me know.

I have never claimed to be the smartest guy around, but wouldn't it make sense to just look up the parts needed for a '91 Reatta, cross reference those parts to other GM cars and get those out of a salvage yard? This way you would have a known working system.
IMHO I have watched a number of attempts to change this system because they don't like the pressure switch and accumulator. Which has a total cost aprox. $200.00 and how much time and $ is spent on these "upgrades"?
I acquired my backup parts by selling used parts at Flint.
I used that money to buy a NEW accumulator from Boorata who had 2 accumulaters and 1 Reatta. Then while walking thru a u-pick yard I saw a switch with the Begium sticker on it. I got it for $5.00. These parts can be had cheap, all you have to do is keep your eyes and ears open and be patient. The most important thing to remember is that one day when you have troubles I can look in a service manual for my answers, what will you do? Ask around for help? Guess? Or if you sell the car[and one day you will], what does the new owner do with a car that is not stock, and the mechanic says "I can't help you"?
I am sorry if I offended anyone, but I just wanted to state my opinion.

See my worry is some one that does not know much about cars is driving there car with the teeves system and there accumulator has been out for some time. Then one day they are driving down the road and the pump, that has been woring over time for the last week over heats aned gives up. Sending the drver and any passengers into the back of the car in front of them. Once the teeves pump gives up there is not a chance of stoppong these cars in a short distance. I almost lost mine the night I bought it, for this same reason. Plus if you motor goes it will cost you $500 for a rebuilt one.
As far as the rest of the issues. A pemanate not under the hood and on the brake mastercylinder and ABS will tell any one who is going to work on the car what system it is and where to find it. Second, the 91' system should comunicate with the earlier computer set up. So all the code shoud be able to be pulled from the TCC and code readers.

I do agree a properly maintained Teeves is as good of a brake system as any other but the key is "properly". Most drivers do not maintain there vehicles the way they need to be maintained. Also I did not like the softer feel in the peadal after upgrading to the camaro front calipers. In my up grade I am keeping the Camaro mastercylinder. This should give me the braking I want and still make for a realistic swap for the 91' set up.

So not to be a wiseguy, you are going to buy all the 99-90 Reattas out there to fix them?