The car sat under cover in a garage since 93, so of course its got some stuff going on from sitting so like, i.e. seals, leaks, etc.

Got the car up and running strong again, at first the carb was choking, and hesitating.

Most intersting thing I noticed though while I just got it around my neighborhood, which is slightly scary, is that the oil pressure is not even showing on the dial. I have to beleive its working, so I am praying to god its just the gauge. The interesting thing is, the gauge does move slightly, but it never gets past the red line, and only when the throttle is open pretty good.

I don't want to drive this car another foot until I'm sure whats going on with that. I have a Chevy CK1500, but I really just started getting into working on Chevy's. Any help or thoughts are appreciated.

...FYI, this is a 305 LG4, 4bbl, 86 Z28, A4 - there are 60,000 original miles on the motor

Next question is the procedure for the rear brakes. I need to get a service manual!

 

Welcome aboard thirdgen.org.

The oil gage pressure sending unit is a common failure item for these cars. Get a new one, replace it, see what happens.

What's wrong with the brakes?

 

Hey thanks for the welcome on...

I'll ask a few questions here if I can:

Where is the pressure sending unit located? (I don't have the shop manual yet, working on getting one)

If the sending unit is the problem, does that mean that the engine is actually not getting pressure?

The rear brakes I believe are the problem. The bump the crazy when applied. I am not really sure where to start, but I imagine part of the work is going to take a machine that I don't have!

Last question; if you were in my shoes and had a car that had been sitting as long as this one, what would you replace? Fuel filter? Oil filter? I know I have to replace the valve cover seals, which I will do, but what else do I need to consider to make this thing 100% road worthy. I've already smoothed out the carb, and replaced the air filter, so it is runing about 95% better than when I got it.

Keep in mind, I don't fully know my way around in this thing yet, but thanks so much for the help. I'll be here a while.

 

Personally, I would go after anything that was rubber. Hoses, belts, tires..... Maintenance the crap out of it. Change ALL the fluids, and filters. Inspect the brake lines/hoses. Probably would not hurt to change the brake fluid. If you have drum rears, chances are good that they are just rusted up. Doing a rear brake job is fairly cheap, and brakes are something you want to work VERY well.

 

Behind the intake manifold.

No, it means the sending unit isn't telling the truth about the engine oil pressure.

 

Thanks guys. I will inventory all the hoses and what not, but most of them are solid, no dry rot. Definitley will flush all the fluids included the rear end, and everything else. The front brake lines are replaced, the rears looked alright.

Is there are procedure posted on hee somewhere for doing the rear brakes. You are correct that they are drums in the rear.

With regards to the sending unit, I will search out that part and replace it. Any special instructions I need with regards to this?

 

Just be careful. The sending unit screws into a brass 90* fitting, and it is very easy to break it off. Unfortunately, it's favorite place to break, is flush with the block... no fun to get out.

Get yourself a real shop manual. Helminc will have the manual that is the most informative, and is what the dealership techs use. I highly recommend getting one. Probably be around 100 bucks, or less. Cheap at twice the price, as far as I am concerned.

Replacing old hoses is cheap insurance. Nothing pisses me off more than being stranded by a five dollar part.....

 

That sounds like fun. Trust me, I will be the guy that breaks it. Any advice on how to prevent that from happening? soak it in oil? work it back and forth a bit?

Any advice on the rear brakes?

 

Yep! Soak it good and let it rest. That's really all you can do.

 

I used an adjustable wrench, and grabbed ahold of the brass fitting, to hold it in place, and prevent it from being torqued over when I tried to unscrew the OPS. Worked great for me.

Pull the drums, and see what the shoes look like, if they are pretty thin, just do a rear brake job, and take the drums somewhere to get them turned. Or, just replace 'em..... See which is cheaper. If the shoes look ok, still get the drums turned, and then readjust your brakes. Make sure the wheel cylinders are good, not leaking, and move freely. (DO NOT step on the pedal with the drums off though, the little pistons in the wheel cylinders make excellent projectiles..... don't ask me how I know this...)

 

The oil press. sending unit is to the left of the distributor. You should see a little canister with a plug connected to it, just behind the left valve cover. The canister is screwed into a brass fitting coming out of the back of the block.(1)Get an adjustable wrench to keep from bending the Bourdon tube(brass fitting) and breaking it.(2)Disconnect the plug.(3) While holding the Bourdon tube steady with the adjustable wrench, use a 19mm socket or wrench to remove the sending unit.(4) Install new sending unit, reconnect plug. It should take about 15-20 to replace if you're not familiar with third gens. The sending unit cost between $14-30.00. I had to replace mine yesterday, put it in before I went work. I used a 19mm stubby boxed ratchet.

 

I am going to inspect it tomorrow morning. Just out of curiosity, will at sending unit off a 350, or a later model engine with fuel injection work? I have a yard up the from my house tht I could pull it for probably less than a dollar. I have an LG4 right now. Thanks

 

Yes, provided that the vehicle you get it off of has an oil press. guage, and not an oil light. Your Z28 is an '86 with a LG4 305, so that means you have a 60 psi oil guage. The donor vehicle's guage will need to have a 60 psi guage as well, for your oil guage to read right. I got my OPS from Autozone for $13.94 and it works fine. I would buy a new OPS vs. a junkyard one.

 

I agree on the new part as well, but sometime I like to expirement on the stuff in the yard before take it to my vehicle and break something I actually care about. I learned a lot doing my 88 Chevy truck, most of it from the junk yard! Seeing stuff ripped apart is helpful.

On a side note, I am waiting for my service manual in the mail, but I want to do some work on this thing this weekend. Are there and pictures or diagrams of where all the common stuff to replace is? I know that's a broad question, but things like the fuel filter, any other filters to replace. Also, If I need to replace the seals on the valve covers, it looks like I need to remove some hosery. I just would like to make sure I'm following the procedure correctly.

 

For the more in depth repairs, there are diagrams. For the rest, they basically point you at the right part, and give step by step instructions. (you did go to Helm Inc and get the manual? Right?)

Practicing on a vehicle that no one cares about sounds like an excellent plan.

 

I went in and took a look at the sending unit tonight. Looks like there is a good bit of oil collecting around the thing, and by the bourdon tube. I am assuming it is clogged in some way and oil is coming out of the sending unit. I hope thats normal for a malfuntioning unit.

 

No, I havent heard of OPS's leaking before. The oil cap is on the left valve cover, it's probably spilled oil from previous oil changes.

 

had a friends car that was leaking oil from/around the OPS, it was an old's motor, but its still a leak from the OPS...........cant remember if it was the unit or leaking from a connection as this was 6 years ago, and i just relpaced the OPS and no leak after


as for the best thing to avoid breaking the tube, PB Blaster, overnight, and just before you work on it