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4 chevys and a ford
614 Posts
Discussion Starter · #1 ·
I am fortunate enough to have my father's 99 Silverado z71.
I got it in 08, and put more miles on it than I really wanted too.
It sits at 150K right now. Its been sitting for a few years, since the bearing on the front drive shaft/diff wore out.
I just quit driving it once I started to feel a vibration, poked around, and found out bearing. I do crank it up and let it run
every once in a while. Ive moved it back and forth in the driveway.

I want to bring it back to life. Its pretty much all original. I had all the fluids changed in 09.
INCLUDING swapping the Dexcool out for green coolant. I had several bad experiences with dexcool.
Its been maybe 40K miles since then. If I could go back, I may not make that same choice. The guy that did the work had a pretty good rep,
and he did not try to talk me out swapping the dexcool.

I am hoping to find a 5.3L vortec enthusiasts who can layout a maintenance/repair plan. The truck was very well cared for. The worst thing its been through
is sitting around for several years....on several occasions. Eventually I will have everything pulled out, and rebuilt, but at 150K , I feel like I can get more years
out of it before a complete rebuild

Were to start? Swapping all fluid again? We all know the horror stories of a trans fluid swap....but you cant just run it forever with the same fluid....

New coilpacks/wires/plugs?

What are things to watch out for? The oil pump? The distributor?

Oil pressure tests.? Leak down test? I have never even used the leakdown test kit I bought years ago.

How about a new radiator?? I had two break on my 01 express 4.3. The second failed between the transcooler, and coolant. That was a disaster. Trans fluid was pumped
into cooling system . That was a mess.

Where to start?
Thanks Y'all

4,257 Posts
Couple common issues to take care of.

Brake lines are known to go first.

Transfer case known case issue which causes a leak

Frame rot in the common areas of the 1500 has caused several to be sent to a junkyard before the drivetrain went bad.

Replacing your plastic coolant parts with aluminum equivalents from later years. The Y heater hose fitting, quick connect heater hose to firewall fittings, and plastic side tanks of the radiator all crack over time.

After that you can focus on the seals and at 150k I would do the knock sensors also.

Doing little weekend projects as well as general maintance will slowly have everything replaced and have you running for 300k.

4 chevys and a ford
614 Posts
Discussion Starter · #3 ·
So when you refer to the you mean all of them? All but the head gaskets?
I definitely get it about all the plastic coolant parts and connectors. All those pieces have been replaced on my daily driver, 01 express.
So...I can find aluminum Y connectors and such? 03 and up?
I guess the first thing to check is the break lines. Rusting break lines is an unusual problem to have here in Atlanta. That is scary.
And of all the trucks I have had over the years, only one has rust on the frame. The Silverado. I assumed that it had spent its first year up north somewhere.
Nothing rusts here in the south, unless it came from up north.
300K would be great. I always wondered why the Vortec engines had two very different designs in those years. My 01 is the 4.3L vortec.
Completely different than the 5.3L . I assume the 5.3l is just a better, more modern design.

4,257 Posts
With the 4.3 you simply eliminate the quick disconect fittings with a small piece of hose.

With the 5.3/6.0 you can run the dorman heater hose kit eliminating the connectiors completly and have the rubber go to the heater core.
Here is the dorman.

So we are talking a 99 with a 4.3?
Somehow I had 01 5.3 in my head.

I have a all aluminum radiatior from OPL that was $100 more then the plastic equivlant and had the trans/oil coolier. Only thing I had to move over was the rubber isolators and it dropped in. Beautiful welds and heavier duty then the plastic one it replaced. But there are 20 or so other companies that make all aluminum drop ins at this point. Just check the reviews.

99 4.3 is a tricky year. You should be able to run some upgraded v8 stuff even if that means you need to run a all aluminum radiatior from earlier years.

Ok so you have that F#$%@ spider with the 4.3.
That is the first thing I would mess with. I consider the spider design a mistake. But if you have it then replacing the failure prone things associated with it like the regulatior, o rings, and checking/replacing sticky injectiors.
I really hate spiders and would be looking for a 5.3 swap if this has a manual transmission vs messing with that horrible spider setup.
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