You can get aftermarket kits cheap but the do not have the quality control of GM, weather or not they are better I'm not sure but doubt it, neither are stronge enough to hold up under heavy use.
The one problem with any kit is getting it properly clearanced for the pump cavity, this is crucial to life and performance. Too tight and it's gonna bind and wear/break and too lose and ya lose pressure.
This is what PTS does to all there pumps and is recomended to be done to all to ensure the best possible results. Not following this is equivalant to playing "rotor rulette"
Quote from Bruce:
*PUMP:
There are two stators used. 150 casting is 81-82, and 088 is casting for 83-90. There are 3 pump bodies used : last 3 casting numbers, 149 (81-82), 082 (83-86) and 690 (late86-90). The 150 casting pump stator will only work with the 149 casting pump bodies, and vice versa. The pressure regulator valves will only work with corresponding pumps too. The valve with a solid valve, no hole, will only work in a 150/149 combo. The valve with the hole will only work in the 088 casting stator. If not, severe pressure problems will result. The 088 stator and both the 082 and the 690 pump bodies will interchange.
We will divide this into two parts. The pump body, and the pumpcover or stator.
*PUMP BODY: First, never use a pump body twice unless you are reinstalling the SAME pump rotor,slide,and veins,
that came out of the running trans. If you are going to reuse,modify pump body as will be explained and reinstall. If pump rotor,slide and or body needs to be replaced start with a "refinished" body. The ONLY way to correctly do this is a tideous and time consuming method. First, our experiance has led us to use GM parts EXCLUSIVLY and they must be ordered in sets from them(GM) at the request of the builder. They must be exact to .002. This is how we do it and have been commended on it by GM themselves:
Use only GM parts ...slide,rotor,veins,all purchased at the same time, all measured at the same time. 10 Vein is more than enough. Reason for increase in vein count, was to try to knock down the pulses or pulsation of the pump. We noticed quite an improvement from 7 to 10 but not much more 10 to 13. We still use the 10. GM actually has 16 different part numbers for slides and rotors. The aftermarket has 1!!!! That should tell you something!!!!
Remove any burrs in slide and rotor. (Yes,even if brand new right out of box is being used,as I have not seen one yet right out of box with no nicks or burrs at all, Not one.) Wet sanding by hand in solvet and sanding edges with 600 or so over GLASS works well.
Wash in hot water and dishsoap and compressed air dry and set aside. The Chrome Moly ring kits have been known to be a little rough too. We wet sand with 600 over glass in solvent the flat edges and then fine wire wheel the circumferance. It is imperitive that the pump rotor and slide are measured very carefully. They MUST be within .002 of the pump cavity depth.
Too loose and line pressure will be low hot, and too tight, rotor and slide could bind, and break rotor, slide,converter neck,or all the forementioned parts. We set them .0013 in the hole, or in the "pocket". The way this is done is, the face is cut, or surfaced. Then another tool bit comes in and with the premeasured rotor and slide thickness', cuts it to .0013 clearence. This is VERY IMPORTANT!!!!!! . The CNC mill then cuts the relieve groove in front to allow more drainback behind seal relieving pressure on seal. (On the 690 pump bodies , Gm did this. On the 082, 149 pump bodies they need to be modified.)
All are done on a CNC machine. That is how they were done originally, and this is the way it should be done now. If you have a good pump body and have the ability to measure it to the thousandth, you could play rotor roulette and get your calipers out and measure 50 slides and rotors before you get two that would fit, PERFECTLY. AND, you could probobly pull it of, but it is not exact. And........another point or intrest would be...... the aftermarket ( parts co's) gives a tolerence of .7071-7076 which is six thousandths and the tolerence for the pump is two thousandths, THIS WILL NOT WORK!!!! It will be either too loose or too tight. See the problem with aftermarket 10 and 13 vein swaps? Now, all the 13 vein rotors and slides I have seen are all on the thicker side of the scale so most will bind when hot if not properly clearenced.
Ok, now we modify the pump return hole by drilling it to 9/64ths. From both directions.
In pump bushing bore the 690 pump bodies have a "step" at which the bushing seats against when installed. The 082, 149 bodies do not, so we mill a slot on three sides of bushing bore 1/4 inch down. After red loctiting the teflon coated bushing, press in hole with arbor press and bushing driver. Then , "peen" the bushing or "stake" the bushing into the milled flats. Flip over , and press in red loctited seal into seal bore. Assemble all pump rotor parts in , of all things, Cam shaft install lube. The red stuff.
*PUMP STATOR:
A hardned stator should always be installed. But there is a correct way to do this and a hacker way to do this. We will discuss the correct way and if anything varies from this it would fall into the other catagory.
Remove bolts from old stator. PRESS out with a press, not with a hammer by beating on. If the stator just falls out when pressed against a bench, ck bore closely for damage, and or walking. Now to install stator red loctite the base surface. Clean the bore cavity real well. Use dowel pins to guide as you press it in . DO NOT BEAT IN WITH HAMMER!!!! after presed in,replace screws with a drop of loctite and reinstall.Stator Guide pin is also OD clutch washer lube. Drill feed hole .040 for feed to washer.Drill seal return hole 9/32 as well. Now after stator has been pressed in , chuck it up in lathe and ck for the stator to be perpendicular to the pump surface. I only see 1 in 20 that is actually perfectly straight...1-20!!!!!!!!!! So then to resurface perpendicular to the stator, we must "parrell deck" meaning you cut the back side of pump , then bring carriage around and cut the front side without moving material being machined, so everything is cut to center....... meaning the stator is EXACTLY 90 degrees to the pump surface. Not doing this is a big cause for front pump failure as if it is not performed,they are fighting center all the time and will eventually bind in cavity. End result,premature pump failure.
Now installing valves and pump blow off.
The use of either a stock pr valve or the slightly modified aftermarket ones are fine. The pressure reg spring should be a little stronger but the stock one is just fine. The 1-2 int boost valve is available in both .300 and .400 sizes for 1-2 and reverse line boost pressure rise. We recommend the .400. The .500 tv boost valve is also recommended with a 5.46 TV boost valve in the works.(More on this to come late spring.) Polish lock up valve and reinstall cking the lock up valve springs for rust or fatigue.
