Do it myself?
Johannes
06-11-2005, 11:38 PM
Hi,
I have a 1991 Nissan pickup and my belts need changing pretty soon, and I also need a coolant flush. I had a few mechanics check out my hoses and they said it's up to me, but I was thinking of doing them, since they are original.
How hard is this to do, because people have been convincing me to do it myself. Is there anybody here that could walk me through it? I have been reading on the net, and reading the Nissan repair manual but it always passes over everything too quickly. I don't want to mess this up. Where is the coolant drain plug, and how do you properly flush it?
Everything in the Nissan book is listed several times over differently depending on what model you have, size engine, 4x4 etc. so it's kinda confusing.
Thanks
I have a 1991 Nissan pickup and my belts need changing pretty soon, and I also need a coolant flush. I had a few mechanics check out my hoses and they said it's up to me, but I was thinking of doing them, since they are original.
How hard is this to do, because people have been convincing me to do it myself. Is there anybody here that could walk me through it? I have been reading on the net, and reading the Nissan repair manual but it always passes over everything too quickly. I don't want to mess this up. Where is the coolant drain plug, and how do you properly flush it?
Everything in the Nissan book is listed several times over differently depending on what model you have, size engine, 4x4 etc. so it's kinda confusing.
Thanks
curtis73
06-11-2005, 11:58 PM
Are you talking about the external belts like for the alternator and power steering? If so, that is a very easy job. If you're talking about the timing belt, I might leave that to the pros if I were a first-timer.
If its the external belts, its as easy as buying new ones and putting them on. If you have a serpentine belt, you use a socket to release tension on the tensioner pulley, pull the old belt off and put the new one on. If its a few V-belts, its equally easy. Pull the old ones off by loosening the accessory mounting bolts to make slack in the belt. Put the new ones on, use a pry bar to put tension on the belts, and retighten the bolts. You should put enough tension on the belts so that the belt can be deflected about 3/4" up and down with your fingers. In the span between the drive pulley and the accessory pulley, push up and down on the belt and it should be able to move no more than 3/4". If its too loose it will squeal. If its too tight, it may cause bearing failure on the accessory. Until you get the hang of it, squealing is better since you can just correct it by tightening up that accessory.
A coolant flush can be messy, but its easy as well. The engine should have one or two drain plugs at the bottom of the block near the oil pan. The radiator should have a draincock at the bottom. I like to have a large pan that covers both drain points. I suggest going to Lowes or Home Depot and getting a "disposable" cement mixing pan. They are large (like 30"x40") plastic pans about 10" deep. They are usually found in the drywall/cement/roofing area, but any big pan will work. Even a 5 gallon bucket will work if you want to drain one point at a time.
Anyway, with the engine cool, open the draincock on the radiator and pull the drain plug(s) on the block. Then remove the upper radiator hose to let air in. Since its apart, definitely buy a new thermostat. They're cheap. Once its drained, pull out the thermostat and loosely reconnect everything and close up the drains. Pull off a heater hose at the firewall and point it toward your drain pan. Using very low pressure from your garden hose, start flushing the system by holding the hose against the open end you just left from pulling the heater hose. When the water coming out the hose runs clear, you're done.
There is one thing you can do to make your flush much more effective. Make sure when you flush that you're pushing water in the opposite direction of the normal flow. It will dislodge junk that has been sitting in there for years. You'll have to use the manual or a mechanic to figure out which one is the supply for sure, but it will make a much more effective job. If you're not sure, just flush both ways.
Pull the drains again and then refill with 50/50 green antifreeze and water. Its up to you if you use distilled or tap water. I've always used tap water, but my water is very soft. Leave that last heater hose un-attached until the last minute so the air has somewhere to go.
Most coolant systems don't need to be "burped" these days since the recovery tank is the highest point, but your manual will tell you that.
If its the external belts, its as easy as buying new ones and putting them on. If you have a serpentine belt, you use a socket to release tension on the tensioner pulley, pull the old belt off and put the new one on. If its a few V-belts, its equally easy. Pull the old ones off by loosening the accessory mounting bolts to make slack in the belt. Put the new ones on, use a pry bar to put tension on the belts, and retighten the bolts. You should put enough tension on the belts so that the belt can be deflected about 3/4" up and down with your fingers. In the span between the drive pulley and the accessory pulley, push up and down on the belt and it should be able to move no more than 3/4". If its too loose it will squeal. If its too tight, it may cause bearing failure on the accessory. Until you get the hang of it, squealing is better since you can just correct it by tightening up that accessory.
A coolant flush can be messy, but its easy as well. The engine should have one or two drain plugs at the bottom of the block near the oil pan. The radiator should have a draincock at the bottom. I like to have a large pan that covers both drain points. I suggest going to Lowes or Home Depot and getting a "disposable" cement mixing pan. They are large (like 30"x40") plastic pans about 10" deep. They are usually found in the drywall/cement/roofing area, but any big pan will work. Even a 5 gallon bucket will work if you want to drain one point at a time.
Anyway, with the engine cool, open the draincock on the radiator and pull the drain plug(s) on the block. Then remove the upper radiator hose to let air in. Since its apart, definitely buy a new thermostat. They're cheap. Once its drained, pull out the thermostat and loosely reconnect everything and close up the drains. Pull off a heater hose at the firewall and point it toward your drain pan. Using very low pressure from your garden hose, start flushing the system by holding the hose against the open end you just left from pulling the heater hose. When the water coming out the hose runs clear, you're done.
There is one thing you can do to make your flush much more effective. Make sure when you flush that you're pushing water in the opposite direction of the normal flow. It will dislodge junk that has been sitting in there for years. You'll have to use the manual or a mechanic to figure out which one is the supply for sure, but it will make a much more effective job. If you're not sure, just flush both ways.
Pull the drains again and then refill with 50/50 green antifreeze and water. Its up to you if you use distilled or tap water. I've always used tap water, but my water is very soft. Leave that last heater hose un-attached until the last minute so the air has somewhere to go.
Most coolant systems don't need to be "burped" these days since the recovery tank is the highest point, but your manual will tell you that.
DRW1000
06-12-2005, 09:51 PM
After you flush the engine you may not have it completely empty when you go and fill it 50/50 so I would recommend looking up the coolant capacity and add 50% of that capacity with pure coolant first and then fill the rest with water. This should get you a 50/50 mixture and compensate for any water that does not get out of the engine prior to re-filling. (although the amount may be insignificant)
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