GMAN
Dedicated LVC Member
What is the best way to do a flush and fill since the Mark dosen't have a drain plug?
Flushing the coolant
- Thread starter GMAN
- Start date
djKale
Dearly Departed Friend
GMAN said:
Doesn't have a drain plug? Look again. Be careful when you flush the cooling system, the service manual recommends you back flush the heater core. I flushed mine last year without backflushing the heater core and low and behold, when Winter came along, my heater core started acting up. It is a serious PIA to replace.
By the time I was done buying coolant and a flush kit, I figured it would have been much easier and not much more expensive to let the local Precision Tune do the work. I think I spent close to $20 whereas a flush was ~$30.
Kale
driller
Dedicated LVC Member
I let the local FLM dealer drain and flush the coolant system, replacing the T-stat and hoses at the same time. No worries. They have what it takes to do it, including properly backflushing the heater coil.
GMAN
Dedicated LVC Member
driller said:
Thanks JP. I think I will inquire with them. It just sounds too complicated. By the way, I found the Cam sensor for $13.00. FLM was $38.00
GMAN
BlackIceLSC
Dedicated LVC Member
I guess shop-key is wrong then...bummer. we just swapped a water pump on our 97, and drained the radiator. new coolant throughout...didnt "flush" anything.
Shop-key goes step-by-step, and garantee's their proceedures by any auto warranty. So, running the engine, while filling the coolant, with the heater on full blast wont flush the heater core?
I beg to differ. If the t-stat is open, and the engine is at or just below operating temps, and the heater is at full blast while you fill the cross-over tube...you mean to tell me the heater core isnt getting "flushed"?
Shop-key goes step-by-step, and garantee's their proceedures by any auto warranty. So, running the engine, while filling the coolant, with the heater on full blast wont flush the heater core?
I beg to differ. If the t-stat is open, and the engine is at or just below operating temps, and the heater is at full blast while you fill the cross-over tube...you mean to tell me the heater core isnt getting "flushed"?
driller
Dedicated LVC Member
Craig, the key word IMHO was back-flush. I only suggested following the manual's suggestions...
Heater Core Backflushing
All engine cooling system flushing and backflushing procedures must include a separate backflushing of the heater or A/C system heater core, after the flushing or backflushing of the engine cooling system, to prevent engine cooling system particles from clogging the heater core tubes and reducing (or eliminating) coolant flow through the heater core. The heater core must be backflushed separately from the engine cooling system for proper backflush water flow direction through the heater core.
The correct heater core backflushing procedure is as follows:
1. Disconnect the heater core outlet heater hose from the return fitting and install a female garden hose-end fitting adapter in the end of the outlet heater hose. Secure with a hose clamp.
2. Connect the female garden hose end of the outlet heater hose to the male end of a water supply garden hose.
3. Disconnect the heater core inlet heater hose from the intake manifold fitting and allow to drain into a suitable container.
4. If a water valve is installed in the heater core inlet heater hose, check to be certain the water valve is open (no vacuum).
5. Turn the water supply valve on and off several times so that the surge action will help to dislodge larger stubborn particles from the heater core tubes. Allow full water pressure to flow for approximately five minutes.
6. If a water valve is installed in the heater core inlet heater hose, apply vacuum to the water valve vacuum motor to ensure proper operation of the water valve and proper closure with no water leakage. Replace the water valve if required.
7. Remove the hose clamp and female garden hose-end adapter from the end of the outlet heater hose and reconnect the outlet heater hose onto the water pump fitting and heater return fitting.
8. Connect the inlet heater hose onto the engine block fitting and intake manifold fitting.
9. Fill the cooling system, as described in this Section using the specified coolant mixture.
10. Test the system for proper heater performance with the specified engine cooling system conditions.
My experience flushing the coolant system of an ole 350 cast iron pushrod was no comparison to the aluminum DOHC cross-flow system. In my particular case, I was not going to chance it. The local dealer used a chemical flush additive and also backflushed the heater core separately as specified in the manual. IMHO, an old fashioned backyard gardenhose 'flush' and refill is not gonna cut it with these coolant systems - at least not mine.
Now when I replaced my factory T-stat with a 160 degree HyperTech T-stat I simply refilled according to the service procedures, but that did not necessarily qualify as a flush.
Heater Core Backflushing
All engine cooling system flushing and backflushing procedures must include a separate backflushing of the heater or A/C system heater core, after the flushing or backflushing of the engine cooling system, to prevent engine cooling system particles from clogging the heater core tubes and reducing (or eliminating) coolant flow through the heater core. The heater core must be backflushed separately from the engine cooling system for proper backflush water flow direction through the heater core.
The correct heater core backflushing procedure is as follows:
1. Disconnect the heater core outlet heater hose from the return fitting and install a female garden hose-end fitting adapter in the end of the outlet heater hose. Secure with a hose clamp.
2. Connect the female garden hose end of the outlet heater hose to the male end of a water supply garden hose.
3. Disconnect the heater core inlet heater hose from the intake manifold fitting and allow to drain into a suitable container.
4. If a water valve is installed in the heater core inlet heater hose, check to be certain the water valve is open (no vacuum).
5. Turn the water supply valve on and off several times so that the surge action will help to dislodge larger stubborn particles from the heater core tubes. Allow full water pressure to flow for approximately five minutes.
6. If a water valve is installed in the heater core inlet heater hose, apply vacuum to the water valve vacuum motor to ensure proper operation of the water valve and proper closure with no water leakage. Replace the water valve if required.
7. Remove the hose clamp and female garden hose-end adapter from the end of the outlet heater hose and reconnect the outlet heater hose onto the water pump fitting and heater return fitting.
8. Connect the inlet heater hose onto the engine block fitting and intake manifold fitting.
9. Fill the cooling system, as described in this Section using the specified coolant mixture.
10. Test the system for proper heater performance with the specified engine cooling system conditions.
My experience flushing the coolant system of an ole 350 cast iron pushrod was no comparison to the aluminum DOHC cross-flow system. In my particular case, I was not going to chance it. The local dealer used a chemical flush additive and also backflushed the heater core separately as specified in the manual. IMHO, an old fashioned backyard gardenhose 'flush' and refill is not gonna cut it with these coolant systems - at least not mine.
Now when I replaced my factory T-stat with a 160 degree HyperTech T-stat I simply refilled according to the service procedures, but that did not necessarily qualify as a flush.