I purchased my C5 last year in August. So far, put new rubber on & oil change, and added new coolant due the level being low last year.

The plan is new set of brakes/rotors & a brake fluid flush. Thoughts on Automatic transmission fluid flush as well while it's in the shop getting the rest done? Does anyone have anything else I should do before putting it on the road?

 

Over time coolant becomes acidic. From time to time a few molecules of CO2 from combustion gasses get past the head gaskets. Over extended periods those CO2 molecules add up. CO2 + water = carbonic acid.

Change your coolant and get a coolant test kit to monitor its condition, most important, PH. In the case of the C5 LS, not all coolant is drained via the radiator drain, some remains in the block. Monitor condition.

Brake rotors generally do not need changing unless they are below FSM minimum thickness. They also usually do not need to be machined unless the pads have worn to the steel backings and scored them. My last set of front rotors lasted through four sets of pads, 16 road course track days and 50,000 miles before they were too thin. No, I never had them machined.

I have changed transmission fluid five times so far, always with Red Line D4 full synthetic ATF. Keep in mind that a fluid and filter change actually removes and replaces half the fluid in the transmission. The other half remains in the torque converter and works.

There are some who advise against a transmission flush. Without a specific incident personally reported and investigated, that may be old wives tales.

 

^^^^^^^^^ That's good advice!

I'll add some variables to your equation:
- Diff and Trans Fluid Flush (should be fresh so often based on mileage)
- Spark Plugs (I don't know, what's the consensus)
- Complete Brake Bleed (should be done every 3 years regardless of usage, more often if great usage)
- Stainless Steel Brakelines (I personally recommend - firm up that bitch)

 

The trans failures after flushing seems to stem from having it flushed by a machine and are hot and miss. I have heard of zero failures using the transmission pump itself to push the old, nasty, oxidized fluid out. Start with a simple filter change and add 2 more quarts than you drained. Pop the return line off the trans case, shove a rubber hose onto it, and stick that rubber hose into a container to catch the old fluid. Start the car, fill the container, refill trans, repeat until you pump at least 3 gallons out. The 4th may seem like a waste, but it will have some particulate in it.

 

Ah, yeah, think. Cycling nasty fluid out of your boxes. It helps.

 

Thanks for this! I added some more coolant late last year, as it was stating that it was low. The brakes/rotors were turned at some point during someone else's ownership, so I'm looking forward to getting them replaced. I'm definitely confident I'll get the transmission fluid changed, I enjoy it in my C5. It could shift a little better in my opinion.

 

I'm definitely looking forward to getting the brakes bleeded. It's a must. I don't even know how these have been functioning so long. Do you recommend I shop around to who can do the Diff/Trans flushes?

 

Yeah Brakes on the top of the list, that fluid by now is totally crud.

For the Transmission...the T-56 is no different than another from Firebird, or Camaro, or Goat...AAA Car Care changed my Goat'ss with Mobil 1 ATF, work a lot better with more protection.

What I do not know, is a option for power flush, such as on the power steering system. You'll have to get some feedback for this, not sure about any options.

 

No need to power flush the steering, can use the pump itself to cycle fluid through. Drain reservoir, plug it and fill it, idle the car with the return line going to a bucket. It'll drain the pump quick, so either have someone standing there to keep it full or shut the car off when the pump goes dry. Also turn the wheel back and forth to purge the rack.

 

Sorry, I don't do manual work.

 

The post wasn't intended for just one person, I'm aware the majority of folks here are either scared to get their hands dirty or old and not able to bend around a car much anymore.

 

You might want to refrain from quoting entire post if you don't intend to respond.

And, you forgot those that pay to have work completed.

 

Imho, I would totally change the coolant. ESPECIALLY if it's Dexcool. As for the trans, I have changed my own, and filter too. Yes, it's a PITA. One real easy way to simplify things that I've found is this. If, a BIG if, is if the fluid is at the correct level before changing, I found a way to refill the trans with the correct amount of fluid. Again, this method only works if your current, old fluid is at the correct level before doing this method for the first time. I put a clear plastic tube into the inspection/fill port, making certain to leave the engine running, and that the tubing sealed reasonably well. The lower end of the hose should be placed in a container. My container of choice was a Mobil1 5qt plastic container. I used this because it has graduation lines. Then shut the engine off. You may need 2 people, and 2 containers. Measure the amount of fluid that drains into the container. Then CAREFULLY pull the pan, trying your best to keep the pan level, reducing the chance of spillage. Then pour or pump with a cheap hand pump that amount into the container(s). Once you do this the first time, you'll never need to do it again. All you're basically doing is measuring the amount it will take to refill the trams back to correct amount again. From that point on, you'll never have to screw around with adding the correct amount again. You'll know the correct amount to add before adding it. Just saying what works for me. With 134,000 miles on my C5s 4L60E, I can't be all wrong....

 

No, most will fit into the 2 categories I mentioned.

 

I'd like to see proof of that - most owners are not that poor.

 

You don't have to be poor to fit into those 2 categories.

 

Whatever, it's obvious what I'm referring to.

 

If you do not have a maintenance history on the car, changing the brake fluid and coolant would be two things to definitely do. Checking all hoses and belts would be another, along with filters.

When I bought my last C5 (used), I had all the fluids changed out just to have a good baseline for a maintenance program.

 

It's obvious you fit into the former of my 2 assertions.

 

No sense arguing, it's clear that you don't know what you're talking about.