Coolant flush procedure

[edwinn]

1997 Riviera

131,020 miles

It's about time to do a "complete coolant change" to use the exact quote from the owners manual. What type of flush machine or process is best, or used at GM dealers? Is the heater hose disconnected? Should a cleaner chemical be added during the process like BG says? I heard one must be careful not to cause problems like gasket failure, etc. when flushing. Back to the manual, it says to USE ONLY Dex-Cool, and for a "complete coolant change" to add supplement (sealer) 3634621. From the Delco website http://chem.rjconlin.net/basepg.php Dex-Cool is #10-101. The Delco website says to use TWO conditioner (sealer) pellets for a six-cylinder.

How would you go about doing this coolant change? Is the BG process any good? I'd like to buy the juice from Delco and have a local mechanic do the job.

-Ed

[danielsatur]

Prestone extended life coolant is compatible with all colors!
Also see Google ''Youtube DIY Auto coolant flush''

[Tech II]

I woudn't use the tablets.....they are usually recommended when the system is opened to replace a part like a w/p......a flushing machine works well....basically the fluid comes out of the engine when the thermostat opens, and that fluid coming out is replaced by fresh coolant pumped back into the engine(machine is attached in series between the upper radiator hose and the outlet of the thermostat housing).......

The "ultimate" way, is time consuming and messy.......disconnect the radiator and heater cores, and reverse flushing with water until clear.......removing the thermotstat, and block plugs, and fhushing out the block.....

Go with the machine....

[enslow]

Here's one of the best coolant flush methods I've seen, plus lots of good advice. It may be for a Grand Marquis, the the techniques apply to the 3800 as well.
http://www.crownvic.net/ubbthreads/u...2501323&page=1

[edwinn]

Thanks guys.. this topic seems trivial but I really want to do it right. The original coolant was in there for 10 years and 100,410 miles. Had it flushed at the local Buick dealer in 2007 and Dex-cool put in. I let it go WAY too long (10 yrs) and 7,000 miles later had an intake failure at the back (driver side) of the plenum, with coolant leaking down onto the trans-axle housing area. GM did a good job in replacing/sealing upper and lower manifold but it was expensive. To hold costs down, I opted to put the coolant back in the motor instead of another "coolant exchange." That was in 2009.

It's been five years and I want do another coolant change according to FACTORY procedure at minimum. Have called several shops and stopped by a few more. Am in discussion with a Chevrolet dealer, with the Asst. Serv. Mgr. and they are using a MOC coolant machine and will put Dex-cool back in. Adding gold Supplement pellets which I saw at the nearby Delcoline wholesaler last week (6-cyl takes two tabs from pack of five, Caddies take all five?) is still up in the air.

See the scans below from 97 Riv Owners Manual. The first view defines the change interval, and the second view defines using the supplement/sealer for a "complete coolant change." This makes sense to me, because a couple shops have said there's been trouble flushing older cars where leaks and other issues develop.







So adding sealer tabs is still up in the air, as one reply above advises. If the manual is specifying sealer, then it can't hurt any? huh? and I believe the small shops that describe trouble after flushing older engines. I'd like to avoid another engine gasket job and/or corrosion of dissimilar mating surfaces.


- Edit -

Here are the Seal Tabs, 10-108. They look like packed fine gold granules.





-Ed

[Tech II]

The only place you are going to open up on the system, is the radiator hose off the thermostat housing...the machine attaches to the hose and the housing......most flushing machines come with their own additive/sealer(which is added after the flush)......I like using them because they are in liquid form, unlike the tablets that have to be crushed and forced into the coolant system....to each his own....

[edwinn]

Originally Posted by Tech II

The only place you are going to open up on the system, is the radiator hose off the thermostat housing...the machine attaches to the hose and the housing......most flushing machines come with their own additive/sealer (which is added after the flush)......I like using them because they are in liquid form, unlike the tablets that have to be crushed and forced into the coolant system....to each his own....

Yeah.. good info. I found a Chevrolet dealer that has a MOC machine which they use ONLY for Dex-Cool jobs. Had an appointment last Saturday morning but was battling ants in the vehicle and had to postpone.

Here's a photo taken while "ant hunting" of a sticker on the driver-side strut tower behind the recovery tank.





Someday I'll tell y'all about the botched strut replacement job!!



-Ed

[edwinn]

Originally Posted by Tech II

The only place you are going to open up on the system, is the radiator hose off the thermostat housing...the machine attaches to the hose and the housing......most flushing machines come with their own additive/sealer(which is added after the flush)......I like using them because they are in liquid form, unlike the tablets that have to be crushed and forced into the coolant system....to each his own....

Had the cooling system flushed last Saturday at a GM dealer (it was REAL quiet there on Sat) and feel I was misinformed about the procedure. They siphoned or extracted the fluid from the radiator cap, and later, the recovery tank has LOTS of debris floating on the surface of the coolant. Some of it looked like aluminum chips. Further I swiped a finger on the wall inside (the tank) which wiped off gray crud clear down to the plastic. This even though I specifically asked to FLUSH the RECOVER TANK thoroughly.













So they charged $101 dollars for 35 mins of work (30 actually) plus coolant, plus flush chemicals. The reason for going there was.. they understood DexCool and had a machine charged with the stuff. This is not up to my standards, and I could have done a better job, at least hosing out the tank.

Cooling System Service

06/02/12 130,982 miles Sterling Chevrolet Coolant Flush
10/04/07 100,410 miles Star Buick Cooling System Flush
09/01/01 84,555 miles Superior Buick Cooling System Flush
10/ /96 0 miles Vehicle manufactured


What do you think? The dealer said they'd run the process again next week if I wanted. Maybe I'LL remove and flush the tank. Hell I used to do that when I was a kid back in the 70's!!

-Ed



p.s. the mechanic said he siphoned it HOT and that got the heater core.

[enslow]

This is the reason I do as much stuff myself as possible.

So they say they understand Dexcool? Obviously not. Not all dealerships have bad service, but I'd have to say this one doesn't make the grade. I'd be tempted to ask for my money back.

[enslow]

There is debate about Dexcool. Here is a good article about Dexcool. http://www.imcool.com/articles/antif...ant/index.html I have heard that they changed the dexcool formulation, but I'm not convinced it will have solved all the problems they had.

Zerex G-05 has been used by Ford for many years now without any issues that I know of. Many people have switched from Dexcool to G-05, myself included. A lot of people say to use the Prestone "mixes with all", but be aware that ALL Prestone coolants contain the 2-ethylhexanoic acid, one of the chemicals in Dexcool that was suspected to cause trouble.

Again, they say the fixed the Dexcool formulation, but I've been around long enough to know that when some one says "yeah, the formulation is fixed", all they mean is that it's changed, but it's too early to know if it's fixed or not. More times than not, it's not actually fixed. I've been burned by that line more than once, hence the reason I switched to G-05.

[edwinn]

Originally Posted by enslow

This is the reason I do as much stuff myself as possible.

So they say they understand DexCool? Obviously not. Not all dealerships have bad service, but I'd have to say this one doesn't make the grade. I'd be tempted to ask for my money back.

Sometimes I think we've all lost our minds!!

This was a GM dealership and I asked the service adviser in person and by email... and still didn't understand how they flushed the system, or what equipment was used. IOW, is the system opened up? i.e. a hose removed? or sucked out through the radiator cap?

Apparently that's what they did.. the radiator cap method!

Lucky to have a three-volume GM service manual here, I scanned the System Draining and Filling Procedure:




Will email this to the Service Adviser, who said they'd run the service again and "clean out the reservoir" but I wonder how thoroughly the young tech would do that? and if it would take him 5 or 10 mins, where I'd futz with it for an hour or more!

They said either I could scrub the tank, or they could "clean it out." The only real way is DIY in this case.

-Ed

[edwinn]

97 Riviera - 131,000 miles

About ready to remove the recovery tank for a scrub.

How does one go about removing these hose hanger clips? Is a little rectangular tool needed?




There's a splice in the Reservoir Tank hose (below) and I could disconnect there and pull hose through the hangers at both ends to remove.




Might as well recondition everything while pulling the tank. That's how things are done around here.


-Ed

[Tech II]

Just pry up the round center of the clip....I use cutting pliers.....grab LIGHTLY and pry up.....

Yes, the procedure does call for the removal or the overflow.....I bet 99/100 shops(especially flat rate), just suck out the reservoir and refill.....

Most times, removing the reservoir, you can't get all the crud off the walls, and you can spend too much time just on that......yours was not bad, compared to some I have seen......especially the ones that have had sealing tablets that have been put in the system....the residue gets "baked" on the inside of the reservoir.....

[edwinn]

Tank scrub successful

Got the recovery tank scrubbed this afternoon. Some photos, tips and issues to present. The radiator cap was cruddy. Suppose I never (or rarely) opened it. Maybe time for a new one? It cleaned up really well with an old tooth brush. Why didn't the shop people mention this?





Next issue.. the lower threaded stud holding the tank was rusted and got 'lunched' when removing the nut. This wasn't good, and I knew better, and even had some Liquid Wrench available. Instead used WD-40.




Wow.. like new

The tank came out GREAT... here's the method used. A coat hanger with a U-shaped bend in the end, hung a rag on the 'hook' and with pliers, bent the wire around 360° to capture it. Then wrap the rag on the end like Rambo would warp a rag around a torch. It was easy to reach every inside corner and surface. The hose was on SO TIGHT that I dared not force it.





Couldn't get much better than this aside from a NEW tank!!








Now back to the shop where they agreed to run the "coolant exchange" again.


-Ed

[edwinn]

This job is a wrap

The local GM dealer were kind enough to REPLACE the previously changed coolant with FRESH Dex-Cool.

That was after I scrubbed out the RECOVERY TANK and cleared the tank hose of an obstruction. Here is an official photo of the tank scrubbing tool which doubles as a spray paint hanger.




There was something caught in the J-shaped bend where the hose section comes around and clamps to the radiator filler neck. I tried to run the outdoor spigot through that short section of hose and the flow was way down. Grabbing tightly around the short end and spigot / hose bib with one hand, and cranking the water with the other, a wad popped out and the flow was restored. Looking for the debris.. I'm afraid it was lost in a LOT of organic stuff around the house and shrubbery.

The coolant probably got in that condition after the intake manifold and gasket job, and the mistake I made was to NOT have another flush done immediately afterward. The decision was to keep the LARGE invoice from inflating further. The wad caught in the tube (from the quick glimpse I got of it) looked like a gray chunk of the sealant from around the intake.


Now the cooling system looks almost like new with fresh fluid!!

Am reconsidering whether or not to add conditioner / sealer pellets if they are going to discolor the tank and stick to the walls. What do you think? One month has gone by and the system has been flushed VERY well. Happy customer, and I'd like to thank the dealer service department for working with me until it was right!!

Have a piece of small diameter black rubber heater hose to go over that lunched stud.


-Ed