Refreshing all fluids
Thread Starter
Instructor
Joined: Mar 2024
Posts: 146
Likes: 98
From: Connecticut
Refreshing all fluids (For HPDE)
Hello again forum,
I would like to refresh all of the fluids, and went down the rabbit hole of seeing what others think is best, what works, what isn't recommended, and what is outdated. All fluids were refreshed 2 years ago, except full clutch.
I have a 1999, 6-speed, 115k miles. It's almost a daily driver 8 months of the year when no salt is on the road. I did a few HPDE last year, got hooked, and now want to set it up to be safe/relaible for one or two a month.
Would someone be willing to let me know if I should not be using any of the following, or if there is something signficantly better for this intended use.
Engine Oil - Schaeffer's Supreme 7000 10w-30
Trans Oil - Amsoil Torque Drive
Diff Oil - Amsoil Severe Gear 75W-90
Antifreeze - ACDelco DEX-COOL
Steering - Amsoil Full Synthetic
Brakes - Castrol SRF
Clutch - Valvoline Dot 4 (no remote bleeder)
Thanks for reading another post about fluids.
I would like to refresh all of the fluids, and went down the rabbit hole of seeing what others think is best, what works, what isn't recommended, and what is outdated. All fluids were refreshed 2 years ago, except full clutch.
I have a 1999, 6-speed, 115k miles. It's almost a daily driver 8 months of the year when no salt is on the road. I did a few HPDE last year, got hooked, and now want to set it up to be safe/relaible for one or two a month.
Would someone be willing to let me know if I should not be using any of the following, or if there is something signficantly better for this intended use.
Engine Oil - Schaeffer's Supreme 7000 10w-30
Trans Oil - Amsoil Torque Drive
Diff Oil - Amsoil Severe Gear 75W-90
Antifreeze - ACDelco DEX-COOL
Steering - Amsoil Full Synthetic
Brakes - Castrol SRF
Clutch - Valvoline Dot 4 (no remote bleeder)
Thanks for reading another post about fluids.
Last edited by RedVlvtChzCake; Mar 4, 2025 at 10:50 AM.
Heel & Toe
Joined: Oct 2024
Posts: 20
Likes: 9
So I recently did similar but for different reasons. Recently picked up a C5 as a daily and I need reliability. I did:
1. All Fluids
2. Filters
3. Plugs, wires were already MSD
4. All hoses with Samco silicone hoses, belts and pulleys
5 Coolant tank had a micro crack, new cap came with that
6. Seats due to annoyance factor but would be real scary on a track day
7. SS brake lines were done during fluid swap, upgraded pads and rotors are on the bench waiting on a warm day
8. I did Hotchkis sway bars which were not necessary but the end links were IMHO, used Moog ones
9. Tires due to age
10. Weatherstripping
As a former BMWCCA instructor I might suggest adding Water Wetter and I've had good luck with ATE Type 200 or Motul brake fluid. Did not see much of a difference with the SS lines but on a track day 20 yr old lines would not give me the warm and fuzzy.
1. All Fluids
2. Filters
3. Plugs, wires were already MSD
4. All hoses with Samco silicone hoses, belts and pulleys
5 Coolant tank had a micro crack, new cap came with that
6. Seats due to annoyance factor but would be real scary on a track day
7. SS brake lines were done during fluid swap, upgraded pads and rotors are on the bench waiting on a warm day
8. I did Hotchkis sway bars which were not necessary but the end links were IMHO, used Moog ones
9. Tires due to age
10. Weatherstripping
As a former BMWCCA instructor I might suggest adding Water Wetter and I've had good luck with ATE Type 200 or Motul brake fluid. Did not see much of a difference with the SS lines but on a track day 20 yr old lines would not give me the warm and fuzzy.
Last edited by c5andc7; Mar 4, 2025 at 04:08 PM.
Racer
Joined: Mar 2016
Posts: 397
Likes: 127
From: Flowood MS
You could always head on over to bobistheoilguy dot com and fall in the lubrication rabbit hole, if that site is still up. You could also check out Lake Speed Jrs. channel on Youtube. Or you could call him and he could talk to you about lubrication until you are overwhelmed with information.
Honestly, I'd address that old clutch fluid first. Other than routine servicing, 2 years isn't a lot on the other fluids if there aren't leaks in your systems. Leaks let contaminants in, and that's what ruins most fluids. Engine oil gets the worst of it thanks to fuel contamination.
Honestly, I'd address that old clutch fluid first. Other than routine servicing, 2 years isn't a lot on the other fluids if there aren't leaks in your systems. Leaks let contaminants in, and that's what ruins most fluids. Engine oil gets the worst of it thanks to fuel contamination.
Team Owner
Joined: May 2001
Posts: 87,325
Likes: 1,588
From: Western NY
I like to change all of the fluids in my C-5, and to that end, I change them regularly. What frustrates me, however, is trying to fully change the brake fluid. There's that "divider" in the middle of the master cylinder, that prevents you from getting in some sort of suction device, so you can fully draw the brake fluid from the front chamber of the m/c.
Heel & Toe
Joined: Oct 2024
Posts: 20
Likes: 9
I use a Motive pressure bleeder that pushes any old fluid out the master cyl. ATE used to have blue and yellow fluid so you could tell clearly when you hit the new fluid coming out the lines but the stupid DOT says that's illegal now and all fluid has to be amber so I just use twice as much to be sure it's flushed, which is 2 liters.
Thread Starter
Instructor
Joined: Mar 2024
Posts: 146
Likes: 98
From: Connecticut
Wanted to update my post in case someone does a search and ends up here and see the list of fluids I was asking about. Please know that I'm new to Corvettes and the list was more of a question, rather than a recommendation.
After too much time in the rabbit hole, I decided to not go with the Torque Drive in my '99. Since I already purchased it before changing my mind, I decided to put 3/4 of it in my new lift/jacks!.
Some people use it and think it works great, and have logged many miles with success. Others express concern of using anything synthetic, or anything other than ACDelco 88861800 Dex III in the early C5.
I have heard that the '97-'00 used cellulose/paper rings in the manual transmissions, before switching over to better materials in the '01-'04. Apparently there may be a risk of the longevity of the paper when using synthetic oil in the early models.
After too much time in the rabbit hole, I decided to not go with the Torque Drive in my '99. Since I already purchased it before changing my mind, I decided to put 3/4 of it in my new lift/jacks!.
Some people use it and think it works great, and have logged many miles with success. Others express concern of using anything synthetic, or anything other than ACDelco 88861800 Dex III in the early C5.
I have heard that the '97-'00 used cellulose/paper rings in the manual transmissions, before switching over to better materials in the '01-'04. Apparently there may be a risk of the longevity of the paper when using synthetic oil in the early models.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
Wanted to update my post in case someone does a search and ends up here and see the list of fluids I was asking about. Please know that I'm new to Corvettes and the list was more of a question, rather than a recommendation.
After too much time in the rabbit hole, I decided to not go with the Torque Drive in my '99. Since I already purchased it before changing my mind, I decided to put 3/4 of it in my new lift/jacks!.
Some people use it and think it works great, and have logged many miles with success. Others express concern of using anything synthetic, or anything other than ACDelco 88861800 Dex III in the early C5.
I have heard that the '97-'00 used cellulose/paper rings in the manual transmissions, before switching over to better materials in the '01-'04. Apparently there may be a risk of the longevity of the paper when using synthetic oil in the early models.
After too much time in the rabbit hole, I decided to not go with the Torque Drive in my '99. Since I already purchased it before changing my mind, I decided to put 3/4 of it in my new lift/jacks!.
Some people use it and think it works great, and have logged many miles with success. Others express concern of using anything synthetic, or anything other than ACDelco 88861800 Dex III in the early C5.
I have heard that the '97-'00 used cellulose/paper rings in the manual transmissions, before switching over to better materials in the '01-'04. Apparently there may be a risk of the longevity of the paper when using synthetic oil in the early models.
