97 Cooling Mods for 95 Inst.

[Don B]

This is my first post so forgive me if the question has been dealt with in the past. I have reviewed many treads about the 97 cooling mods but I have not seen were the question of interchangeability has been addressed. I have a 95 Suburban that I am contemplating installing these mods and have the following questions;
1) Will the 97 style dual t-stat cross-over tube work for a 95 installation or are there fit issues that require specifically mfg. parts? My thought is to search wrecking yards for a donor.
2) Are the 97 HF pumps 2 way interchangeable with the 95 unit and if so are there any benefits or cautions that I should be concerned about?
3) The vehicle currently has 160K miles on it, I am replacing the head gaskets, motor mounts, water pump, and t-stat, are there any other parts / material I should be considering while I

[gmenor]

I ordered JK's high capacity water pump instead of rummaging around. The install was pretty easy except for the engine bracket for pulling the engine out (modified it with a 4 inch grinder). If you are going in that far I would suggest the dual idler gear that JK also sells. Ronnie Joe has or had reservation about it when I first questioned about it. I don't have the link but, what Ronnie Joe had to say is well worth reading and may sway your decision (my decision was I had already ordered it). There are pros and cons about it but, I installed it and never look back. It is very responsive, cranks up fast and well worth the money.

[rjschoolcraft]

The alternator bracket will need to be modified slightly for fit. Grind to remove stock as required.

I did have some reservations about the gear drive, but will be installing one in my new engine. My concerns had to do with the high frequency torsional vibration that the gear teeth will impart to the crank shaft. Enough folks have run them long enough now, that some of my concerns have been reduced. I also think that a balanced and blueprinted assembly reduces any risk that might be there.

By the way, does anyone have any idea how much power is required to drive the cam shaft?

[Barry Nave]

Gear drive, 32K love it. Had timing ck. Still dead on.

[dstoops]

Welcome Don,
I purchased my '97 cooling kit from Peninsular Diesel. I don't remember the price but they were very helpful and answered all my questions before I even bought anything. Minor grinding was required on the aluminum accessory bracket in order to clear the larger water passage. The kit included a new water pump which failed after about 12 months. They sent me a new one and warranted it after I sent the "leaker" in for them to inspect. Good people to deal with.

[Don B]

Thank you for the information and suggestions. Are there any problems or concerns with installing the HF pump without the duel t-stat installed? I

[tom.mcinerney]

I know this has been done , i believe there is negligible benefit until the T-Stat is added.

[damork]

Don B,

Here's a collection of photos I took while doing some of the work on my truck. It might help give you an idea of how it works on a 95. I did this with about 160k miles and now at 202k. The temps are far more constant now than with the original setup.

http://community.webshots.com/scripts/misc.fcgi?action=invitePickup&uri=album/42727688JuUMeK

And here is a breakdown of the major parts I used to do the cooling upgrade:

Quantity GM Part # Description Total
1 12553405 Housing - Crossover Manifold $78.93
1 10154688 Engine Crankshaft and Camshaft Balancer (Harmonic Balancer) $67.81
1 15683910 Radiator Hose Lower $31.54
1 12564276 Water Outlet $34.14
1 15977350 Radiator Hose Upper $12.48
1 10243629 Hose $2.39
4 24504922 Thermostat Water Hsg Outlet Bolts $1.88
1 15010202 Engine Fan Blade (from Duramax - fits 97 Fan Clutch) $33.87
1 15022302 Engine Air Cooling Fan Clutch (1997 VIN S 6.5 Diesel) $56.62
Total Fall 2002: $319.66

[Don B]

Thank you for the information and photos. Can you advise if the crossover housing and t-stats were dealer items, the price looks reasonable and that is not usually the case when it comes to dealer purchases? Can you also tell me if the water pump was a standard HO 97 pump or was a specific pump required and was any modification work needed for the installation?

[damork]

Don B,

All the parts listed were current for the 1997 model year when I bought them in 2002, except for the Duramax fan. I bought them from Team Chevrolet of Scottsbluff NE. Here's the link:

http://www.teamchev.com/

I believe the last time I ordered from them I talked with Gale after inquiring over the internet. They are great to work with for internet orders - which is where they offer the price breaks.

Prices shown included shipping, shipping is free once you exceed a certain amount but I don't remember what that amount was. The water pump is the HO unit.

I went with 180F Robertshaw thermostats and so far temps been very constant compared to the old setup. I tried the 180F single Robertshaw with the 95 year hardware and even when not towing the temps would drift up easily.

With the temperature stability I've observed, I may go back to the 195F thermostats as there is some gain in efficiency. I consistently get 18.5-19 mpg with my current setup. I know from records I've kept that the hotter thermostat means 20-20.5 gpm unloaded at 65 mph.

[Don B]

Thank you again for you suggestions and help. I am also considering the Dmax fan setup as you have installed. If I decide to go with this mod I understand that the clutch will also have to be replaced, no big deal as I am replacing it with the HO model anyway but need to know if the new clutch is compatible with the 97 HO pump. Additionally, are the Robertshaw t-stats readily available or will the standard 195 unit from the local Auto-Zone work as well?

[damork]

Don B,

All the parts bolt up together. I bought the 97 clutch and chose to use the Duramax fan. I never had to trim anything from the shroud to use the Duramax fan, but some people have had to.

With respect to thermostats - Robertshaw used to be available from Autozone but they switched to something else. I understand Checker Auto is now selling the Robertshaws reboxed. I buy locally from Murray Autoparts and John Kennedy is another source. I've never had to order online because I've always had a local source.

Robertshaw has had a good reputation, but you can go with GM, Stant, etc.

[Don B]

damork,

Thanks again for all your time suggestions and help. I have ordered all of the 97 upgrades from the source you have listed, Team Parts, and saved approx 40% off the GM list price. With that said, I do have to give some recognition to GM for the 10% discount they gave me on the one item Team Chev was not able to provide, the water outlet which was just enough to cover the sales tax. I am waiting for the pieces to arrive hopefully in time for the weekend put-back-together party.

On another subject, I have also decided to install the Tru Cool H7B trans cooler and pan mounted temp sensor while the radiator is out being flushed and I have access. The question I have is the

[Billman]

RJ

Is that a Trick Question?

[rjschoolcraft]

Originally posted by Billman:
RJ

Is that a Trick Question? No. I simply want to do some analysis on the gear drive and need to know how much power is required to drive the cam shaft. I'm sure I could come up with an estimate, but thought I'd see if anyone had a good number.

[Marty Lau]

One suggestion a rather minor one is to scrap the quick connect on the heater hose to manifold and put a brass hose nipple and piece of heater hose with hose clamps on. Makes life better. smile.gif

[Don B]

I am in the process of installing the remaining pieces of the 97 cooling up-grades and have come up against a couple of problems;
First there is/was considerable interference between the belt tensioner / alternator brkt. and crossover housing which resulted in the grinding a considerable amount of material from the alt.brkt. in the webbing area. I have read in previous posts that grinding of the brkt is expected but was surprised at just how much material needed to be removed. Should I be concerned about diminished integrity, and have failures of this brkt. been seen as a result of this mod?
Second, at the advice and suggestions of the form members I ordered and received 2 Robertshaw 330-180 thermostats. Upon inspection of the units and reviewing the photos of the Robertshaw t-stats on the 6.5TD Cooling Solutions That Work article it appears that these units are not provisioned with the sealing o-ring usually found on production stats. As the 97 stat housing is not addressed in my 95 shop manual I am curious as to how the t-stat housing is sealed.

[rjschoolcraft]

It does require a fair amount of material removal from the bracket. No failures have been reported.

I reused the seals from the factory t-stats. You can buy these, though, from about any autoparts store.

Good luck.

[Marty Lau]

Originally posted by ronniejoe:
It does require a fair amount of material removal from the bracket. No failures have been reported.

I reused the seals from the factory t-stats. You can buy these, though, from about any autoparts store.

Good luck. I too was suprised at the amount of grinding but no problems, and NAPA has the seal for the T-stats for $1 vs dealer of $4.