J2571

Few weeks ago, I started to see a rust stain on the garage's floor after driving the car under rain. This past Sunday, I checked the car for rust on the frame (caused by a battery leak) and it was found a severe acid leak. I changed the car's battery just few months ago and never before I had the rust stain. Therefore, the acid leak is caused by the new battery.

I will be making a battery replacement (for a gel one) and doing the rust repair following the recommendations from the "Battery Acid Repair" posts.

Note: My corvette is a 2001 Z06.

Previous to start the rust repair I have the following questions:

1) How much time may be the battery fully disconnected (removed from the car)?
On my wife car, I fully disconnected the battery from the car by two hours and after started the car it was not running well due to the full removal of the battery so long time, the car's computer need to bio re-programmed.
Does the Corvette may be suffering by the same restriction / issue?

2) By how much time may be the PCM module removed from the car? Is there any timing restriction for the PCM removal to avoid further problems?

feeder82

doesnt matter in either case the flash memory in pcm wont be affected by removal or battery removal

zz28zz

I remember reading something, a few years back, abt batt acid leaks causing some serious damage to the cars wiring. If I remember right, there's a bracket under the batt box that can funnel the acid right onto the computers wiring harness causing all kinds of problems. Better check for that while you're cleaning up.

I remember reading that and buying a gel batt the next day.

Another issue I ran into after replacing batt:
After batt has been reconnected, the A/C blend doors run from one hard stop to the other to find their limits. Sometimes when they hit the stops, the plastic gear inside the actuator will crack and the blend door will stay wherever it was when it happened. I had hot air on drivers side and cool air on pass side. Not good in the middle of summer.
I cringe every time I have to disconnect the Vette batt..

Good luck.

dadaroo

If you think any acid got on the PCM or TAC modules/connectors you need to remove them and make sure they are cleaned. Remember it may still be too early to see corrosion signs on the connectors/pins. I would use a spray battery acid cleaner/neutralizer and then thoroughly flush with water and let dry before reconnecting. Make sure you disconnect the NEGATIVE battery cable FIRST before you remove the any modules and/or the battery.

LR'z-Z06

Some of the aftermarket companies sell a battery Matt to absorb acid if it leaks. This might help keep it off the computer and wires.

Coc5

I haven't seen this covered before, so I will add this.
Not only will a battery leak remove the frame paint, get on wires, it also can get to the vacuum reservoir canister that is back there also.
I had a battery let go and I got on it right away. Washed everything down, painted the frame. Well, back behind there is the vacuum reservoir. There is a little vacuum line runs to from the back of your intake, to the reservoir and then to the inside of the vehicle. The acid cracked the reservoir, cracked the vacuum lines and I had a vacuum leak that was from hell trying to find! That was the cause of my high idle when I would shift. I have a standard. The idle would drop, but much too slow, so I knew I had a leak somewhere.

J2571

Thanks for the help.
Today, I started the project: the battery was removed (negative terminal first) and the PCM was removed too.

The corrosion is huge: cables bundles are corroded (a section of the plastic covers dissapperar on two different bundles), the frame is corroded on varios sections, the PCM case is highly corroded and a section of the cable insulation on one of the cable on the PCM wiring harness was lost.

Areas and wiring harness were cleaned, the rust was removed (by the way, there is a Rust - Oleum product that it is very good product removing the rust) and the frame was painted with a special primer. Rest for tomorrow: paint the frame and clean & remove rust from the PCM case.

Tomorrow, I will post some photos of the before and after and the products used.

Hope to crank it and all is ok.

jcgunn

What (POS) brand battery was this?

Bill Curlee

I have seen this issue 50+ times.... The MAIN resolve is to neturalize the acid from the leak with a baking soda/water mixiture or professional acid nuteralizer.

Then to properly convert the bare frame/rusted area with a rust converter product and then preseve and paint the frame and the rusted areas with a semi gloss paint! Then repair the damaged electrical stuff!

I use PPG semi gloss paint to coat the converted the prepped and primed frame.

Until you get rid of the acid residue, fix the frame corossion and make sure that ALL the ELECTRICAL CONNECTORS in the damaged area is acid damaged free, you have work to do!

BC

Bill

robert miller

good remarks here, and you are correct on your remarks.

f6john

Give us some details about your problem too. I notice you are new to the forum so how long have you owned your C5? Do you know the age of the battery? Looking at the old battery before you removed it, were there any telltale signs that might have alerted you to an impending problem? Are you going back with a lead-acid battery or an AGM type battery?

J2571

Well, the job was completed past Sunday. Thanks you very much for all the responses and support provided. They were very helpful.
Raining weather delayed the project since the paint was sticky after 4-5 hours then; I left the installation of the parts for the next day.

I need some help on how to post the photos here on the forum. Any help/suppoprt will be appreciated and then I may post the before and after photos.

The job was performed following your suggestions:
First, the impacted parts were cleaned / “neutralized” with a baking soda/water mixture (a sticky paste was formed and used) and rinsed with plenty water.

Second, I used a rust stripper to remove the rust, rinsed with plenty water and then, use the scrubber mat. Being on the auto store (PepBoys) I observed a Rust-Oleum Rust Stripper (made of an acid base formula) and decided to prove it. It was very good removing the rust, it leaves the metal surface bare without rust then, reducing your time with the scrubber mat and/or the wire brush. The stripper bottle come with a scrubber mat that is very useful removing the rust. Just follow the bottle's instructions.

Third, for the little remaining rust, I used a wire brush on a cordless drill and a Dremel with wire brush (for the smaller places). A clean cloth and air was used to clean the areas from the small debris.

Fourth, the bare frame/metal areas were painted with a rust converter product (Rust Oleum, Rust Reformer on spray) and then finally painted with a gloss paint (semi-gloss paint was not found at two auto stores).

Note 1: For the PCM case, the rust stripper must not be used. Then, the PCM case was cleaned with a baking soda/water mixture, the scrubber mat and the wire brush.
Note 2: When cleaning the PCM, be careful when handling the wiring hardness rubber seal. It is glued to the PCM case but easily tear off. I was not careful handled it and the rubber seal was tear off. The only way to put it back was gluing it. I used super glue to re-install it and it worked.

Fifth, the damaged electrical stuff was repaired.

Sixth, all the parts were re-installed, the car was cranked, proved and all was OK. Thanks you again for your help.


See below some more details as requested:
The battery that caused all of this disaster is a Bosch part number 75-730B. It is not a maintenance free battery. It was acquired on May 2013 following the auto store recommendation. It is my fault that I did not found this forum previous to acquire that battery. If I would do it, all of this matter would be avoided. When the issued battery was installed, I checked the battery tray and below it and there was no evidence of major acid leak, all look OK.

My experience with this 2001 Z06 (my first GM car) is few, I acquired it on April 2012 with only 35K miles on it. It is my Sunday’s car then, from that date to now only 3.5K has being added to it. I had made the following repairs on it: new OEM clutch (new clutch, plate and flywheel), new master clutch and slave cylinders, slave cylinder remote bleeder line and a Powerbond underdrive harmonic damper.

Bill Curlee

Glad ALL the info provided allowed you to solve the issue..

BC