Saab 900 restoration/maintenance

[marlinspike]

Saab had a few unique tools, like the one for the clutch. I think that kind do work, they just look a bit scary to use. I was thinking of buying a used hydraulic spring compressor but they look pretty scary to use too lol.

 

[DennisCA]

I decided to reassemble the steering gear assembly with pump and reservoir on the bench, raised the reservoir up so it would sit about where it does in the car. I have a 1400rpm motor that drives the pump. This way I was hoping I can avoid doing a pointless disassembly of the rack and figure out if I got more than one leak.

No leaks at the reservoir that I can see, but I cut a few centimeters off the hoses that connect to the reservoir, so that might have helped that problem.

Direction of rotation on the motor pulley is clockwise, which I believe is correct.

The motor is wired in and the right rotation was figured out before I put the belt on, I had to swap two phases. Then I fitted a small knob on the gear so it should be easier to turn it.

And soon after I filled the fluid and bled the system (by moving the rack back and forth many times), I can see this:

So definitely a leak on the top of the pinion.

I don't see any leaks at the pump or hose connections so far. I'll leave it for a while and see if there are any other leaks.

I've added blocks of wood on the sides of the rack which I screwed into the bench, to provide resistance for the system and the pump does work harder then. I think I need to add more rigidity to the system however to increase the pressure. I want to see if I get leakages anywhere else. So far only the top leaks. But perhaps that's all there is then.

 

[DennisCA]

I've been using the bench setup to crush pieces of wood to put some strain on the system. I screwed down some wood pieces and used the racks inner tie rods to exert force on them. By doing that I could verify that the system wasn't leaking elsewhere.

Anyway I disassembled the rack pinion housing as that''s the only place found to be leaking. The repair kit I bought I found lacks the correct upper hydraulic seal, instead I got two of the type that goes on the bottom end. 19018211B-CORTECO seems to be a suitable seal for this so that's been ordered. The old seal is hard as a rock and I suspect that's why it leaks.

The bottom bearing is 10x30x8 mm and it's easier to find, though not that common. At least I got the valve seals and o-rings for all the hose connections and so on. No leaks detected there but I'll take the opportunity to replace all o-rings there anyway.

 

[DennisCA]

Bearings are harder to find than I thought. If I am satisfied with a chinese bearing then yes they can be bought. But none of the reputable bearing makers have it. A possibility is machining a ring and using a 10x26x8mm which is a standard size. Though I think I'll re grease the original bearing.

 

[marlinspike]

Bit late but I came across a guide here when I was looking for something else:

Rebuilding Rack & Pinion C900

 

[DennisCA]

I believe I've read that one, I remember the tip about the boiling of the teflon seals, though I've seen others say they stretch theirs on a mandrel and then compress it again using tape (or hose clamps). I've got the complete Saab service manuals as well, I spent a week looking at various guides and posts on saab forums before hand. I always try and get as much info as I can before I start something new to see what kind of pitfalls or tips I might pick up for certain moments of the job.

I haven't had time to change the valves yet, bit busy during the weekdays.

Last night I also got new front shocks, Bilstein B4s. Might as well when redoing the whole suspension.

 

[DennisCA]

Still waiting for the seal so I'm working on something else in the meantime.

I've removed the spring on the right side with this tool I bought so I can change the bushing in the spring cup:

The quality of the tool is so-so, this is probably because they didn't chamfer the edges at the factory so it digs in. I feel should take the tool apart and chamfer the edges, also grease the sliding surfaces in addition to the screw.

I went to work on the spring cup with an angle grinder and a wire brush, then I painted it with brake caliper paint.

I removed the control arm mounts and pressed out the old bushings, they weren't really in that bad condition, although they didn't like being pressed out.

The rear bearing bracket, however, had a lot of galvanic corrosion where it contacted the shim, I should get a replacement today.

I also removed the shock absorber and the lower bushing was probably really worn out.

 

[DennisCA]

I have re-assembled the steering rack pinion gear and have been testing it for a few days now and not seen any leaks. Looks like I can reinstall this soon, I'll replace the sway bar bushing before I do that because I have easier access to them now.

I got a new mount for one of the control arms too as the aluminum in it was corroded.

I've also ordered a set of sport springs, Lesjöfors.

 

[DennisCA]

Removed both front springs and have been pressing out and in bushings

I don't have a dedicated tool, just what I could improvise with. This for example is a 32mm spacer sleeve from a horizontal milling machine arbor.

And just look at this bushing, it looks like new despite having being pressed out, I'm very impressed. It's in such good shape it was almost pointless change it, the replacements for these are NOS Saab originals too and they look pretty much the same.

The new bushing goes in without a problem. Used silicone grease as lubrication. Here I'll take the opportunity for some rust treatment before putting the spring back, Dinitrol ML on the rust spots to neutralize the rust, then after it's dried some thicker goop to cover it.

And these bushings... more worn than I thought, like a hot dog down a hallway... and I could have ordered these back when I bought the other bushings...

I didn't expect to spend all of sunday mostly on this. One of the lower control arm bushings had rusted completely against the control arm and was impossible to remove. I got the bracket off the control arm using a bearing extractor but the bushing was still stuck. I removed the rubber (burned it off) but the inner sleeve was still on there, I tried heat (spot welded it multiple times with the mig welder) but finally I took the angle grinder and ground it until I just about went through the inner ring. Then I was able to pry it off, finally.... The metal will change color as you've almost ground through so I used that as an indicator and ground until I had a long strip that was a different color, then I very carefully ground off the last tenths of a mm. I still got a small mark on the control arm but it's slight. You can see it on the photo.

I think I'll throw the control arm in an electrolysis bath now. Might as well try and make it look nice, repaint it perhaps.

 

[DennisCA]

Painted the mounts then paint them again with stone chip paint.

Control arm painted

I took the opportunity to adjust the gear shifter linkage when I had the steering rack and sway bar out. I've heard you should use a 6mm rod here but I had to use a 5mm rod.

And a 6mm rod inside the car, screwdriver fit the bill.

And of course.... Stumbled on some more needed welding. This is an MOT fail so I gotta get it done. Might as well get the driveshaft out. At least it doesn't feel like it's that structural, the rest of the beam is much beefier. But I've already bent up some sheet metal from 1.2mm sheet but maybe I should use the 2mm stuff instead, the left hand side which is intact feels like it's about 1.2mm.

That's some ugly welding. Time for some grinding and paint

It's still a bit gnarly but the main thing is it's solid.

And now finally parts are starting to go back into the car instead of out of it. Both lower control arms are ready to go back in

Right side drive shaft got a new gaiter for the CV joint and I also cleaned and repainted the shaft.

I got a tool for clamping the gaiters in place too.

Also got the servo pump and steering rack wrangled back into the car which was a real pain. The gaiters came loose from the rack too, the rebuild kit provided zip ties for holding them on which are really useless IMO. I'll have to buy some proper clamping rings or hose clamps.

 

[Rannsachair]

The control arm design looks the same as on my old Saab 96.

I should stop reading this thread, I keep looking at Saab 900's for sale!

Nice work, keep it up: my favourite car.

 

[DennisCA]

I had to go look them up (you can still buy them newly made for the 96 and the 900) and they look identical, but they are not compatible.

96

Bärarm Höger, NT

93,95,96 1956-1980Fram, Nedre Höger sida.Svensktillverkad.Ytbehandling: Förzinkad.

saabklubben-reservdelar.se

900

Bärarm Höger, NT

99,90,900 1973-1993Övre Fram, Inkl, bussning till fjädertallrik.Höger sida.Svensktillverkad.

saabklubben-reservdelar.se

 

[marlinspike]

What did you paint the control arms with, Dennis? I am derusting some at the moment but not sure what paint is best for rust proofing/longevity. I want a black satin finish I think.

A search on here suggested most people just epoxy primer then 2k top coat them. I have some black Rustoleum combi color which I've used in the engine bay (car is black) but it's glossy.

 

[DennisCA]

My original plan was to phosphate them and soak them in boiled linseed oil but equipment failure made me instead just paint them with 1k brake caliper paint. Then stone chip paint on top of that. Stone chip paint is thick and elastic and oil based so it has some anti corrosive properties. I figured this is good enough for a car not driven in salt anymore. I might redo it in the future, I would like to zinc plate and yellow chromate them.

 

[DennisCA]

I put the lower control arms back on, reinstalled the new spring set too

I removed the expansion tank to better be able to install the left shock, really no room there. Found rust under the tank, I've applied raw linseed oil and once it's had some time to work I'll brush some thicker goop over it and that should stop the rust from progressing.

I had to buy a set of "crows feet" to hold the nut in place, then I made this tool and I turned that to screw the shock in place.

Imagine a pair of vice grips on the rod and that's basically how I did it.

Reinstalling the lower control arms and the sway bar was a hassle, I had to go back and loosen all the sway bar bushings again, I had to loosen the steering rack again as well. Then I had to first install the sway bar and end bushing on the control arms on both sides, then once both control arms were installed I could finally fiddle in the bushing and clamps that hold the sway bar to the body. Not too difficult, but figuring out the correct order was a PITA.

Spent all evening on that and just as I was done I found the CV boot on the left side has split!!! I just replaced the right side...

 

[DennisCA]

The Saab is resting on its own tires again, the water pump, power steering pump, belts, etc are reassembled, I thought I'd flush the cooling system next so I'll take out the thermostat.

Nice... Looks like it leaked here and they tried to seal it with silicone. The gasket was in really bad shape. Maybe it was installed incorrectly or reused.

After I tried to clean it, I hope it won't leak with a new thermostat and gasket.

I took off the thermostat housing at the same time and went over it with the wire brush

The inside doesn't look super good but I've since tested it and it seals fine.

Now I've driven the car with water and a dissolved dishwasher detergent tablet in the system. Drove with the heat on max in the car, went around the neighborhood with the windows open. The thermostat was not installed for this.

Afterwards it was left to cool down for an hour or so before I drained it. I drained the coolant as best I could into jugs, I have to say the Saab is not as nice and easy to change fluid in as the 850 is.

Then I flushed the system by removing this radiator hose and shoving in the garden hose, flushed till it ran clear.

Also removed the lower side of the radiator for this:

Also flushed out the expansion tank. Then I used compressed air in the hose that goes to the thermostat housing, that got several more liters out, I repeated this procedure a few times. I also pushed the garden hose into the radiator and rinsed it out as well.

Now it's pretty late and I'll leave it like this until tomorrow, then I'll fill up with de-ionized water and G48 coolant.

 

[DennisCA]

OK today I ran water through the system a few more times before filling up with coolant again.

Took a test drive and gassed it up, this is with lowered springs in just the front, I got a pair for the rear suspension too but this looks nice as is.

 

[DennisCA]

I found a picture from last year, the car looks like it was sagging in the rear by comparison, likely the rear springs are just old so it sits lower.

 

[DennisCA]

Last week I got a professional wheel alignment done. I got negative camber on the front wheels now. Saab specs say positive camber 0-1 degrees, unfortunately it's such a PITA to modify camber (and caster) on the left side that we decided to instead make the negative camber more equal instead. Fortunately left side caster is in spec, right side caster wasn't so it got altered by removing two shims on the front. Super easy on the right side where you got access.

Final values were:
Toe in total: 0.18 degrees
Camber: -1.4 left, -0.6 right
Caster: 1.8 left, 1.9 right

Now it drives real nice though, straight as an arrow.

My next problem was the right handbrake wire was sticking, today I installed a replacement which wasn't as bad as I thought. Then I cleaned the car inside out.

Cats made it difficult to get the inside clean, they staid in even when I brought the vacuum!