I was reading in the archives that some of you don't like plastic oil press lines for your gauges. Mine is over 20 yrs. old so I guess I should replace it. Should I use copper or plastic? The one I have now is somewhat hard black plastic, it's more than a 1/8th " OD. Mine comes off the engine between the first 2 front spark plugs on the driver side. Then it goes thru the f/wall in the clutch linkage hole which I'll be replacing the boot so I will have to put it in somewhere else. Where do you guys put the hole for this line. When I unscrew it from engine how much oil will come out, any? Thanks

[ 12-13-2003, 11:47 PM: Message edited by: RamJam ]

The line you are talking about is the water temp gauge. The oil line comes from the rear of the block by the distributer.

It is probably your oil line IMO, never seen a plastic water line. Sometimes oil pressure gauge lines can come off the plug right above the oil filter.

Anyway, whatever type of line it turns out to bee use copper because plastic can blow off the fittings or melt if there is a lot of heat. Play it safe and go with copper tubing. (actually if your line a temp line, you probably do not want to cut it because that line is usually filled with something other than coolant from your engine)

I have a couple holes that I use for running wires and tubbing through the firewall. It doesn't really matter where or how you run it through the firewall, only that you do it in a way that does not interfer with your gas or brake pedals or run against a sharp edge that can cut the line.

You can install a split rubber grommet in the hole to guard against sharp edges. Available at your local hardware store. Also, don't drill your hole so high on the firewall that it winds up in the windshield wiper linkage well. Someone I know did that. graemlins/clonk.gif

A mechanical temp guage has a solid copper line encased in a plastic insulator and is larger diameter than oil pressure line. If it's coming from the driver side head it is for water not oil. My stock guage has a cloth insulation making it about 3/16" in dia.

Your oil pressure or oil warning lamp should connect on the back edge of the block on the driver side of the distributor...

I wondered about that being water temp line but I didn't think with it being that flimsy it could have copper in it and I knew it couldn't be just plastic for heat temp reasons but if you say that's where it comes out then that's what it is. So if I unscrew it from block will plug have to be replaced too or will it reseal?

I guess I have the same question for the oil press line on back of motor and how much oil will come out after sitting for over a month? Thanks guys

Not too much oil should come out. Mine had been on for over 20 years, & the idiot light sender started leaking. When I went to change the sender, the nylon gauge line broke off at the tee (brittle from age & heat, I guess). I only lost about a teaspoon of oil, & the engine had been running an hour or so before. I cut off about 2" & replaced the ferrule for a temporary fix. The engine will soon be replaced, & I'll use copper line then.

On my 350, the oil line connects to the motor close to the distributor on the driver's side. You'll see it. There is no pressure when the car isnt running. But there will be a small amount of oil in the line. ( If you have a mechanical oil gauge (oh boy, here we go again)I strongly recommend using the search function for this. I and others had a rather lengthy but thorough discussion regarding this. I'll try to link you. Its all the info you could want, and then some!
http://www.camaros.net/forum/ultimatebb.php?ubb=get_topic;f=9;t=011201#000000

I started to read that link.. Thanks, I don't think it will help much in my case. My gauge isn't stock. It's a Sun from early 80's so I don't think ferrels are the same, but maybe they are I'll read more of that lengthy post tomorrow night. smile.gif Can I get that copper tubing from local auto parts store?

Can you answer my above questions on the water temp line which is also a Sun gauge. Thanks

If its a temp line just leave it alone unless there is something wrong. If it has been on there since the 80s then I don't think you will suddenly have any problems with it because its plastic.

I re-read your first post more carefully and if it does come off the head between the front two spark plugs it is definately water. Have a bucket handy if you mess with it - you might loose a half gallon of antifreeze when you unscrew it.

Eric,

I guess I'll let it alone. The oil one though I have to look at that one. I checked Summit site and saw I can buy the same exact gauge for another $8 more than what the copper line kit will cost me. Do you think it will be as good as the one I have now? I'm pretty sure they made them better back then. Thanks

You have a mechanical temp gauge - the line from the gauge to the sender bulb in the head is sealed and gas-filled, and if it cracks or breaks, the gauge (and line/sender) are history.

Copper tubing isn't a good idea for an oil pressure line - it work-hardens with vibration and will fracture eventually. The original OEM lines that LOOK like copper are actually copper-plated STEEL. The OEM (and reproduction) black "plastic" lines with the internal brass reinforcement are made from an engineering-grade nylon material and are very durable; the aftermarket white plastic lines that come in low-buck gauge kits may or may not be as durable.

John,

Thanks for the info. Before I read this I tried to remove the water temp from engine and I couldn't get it out so I guess that's why. So tell me what can I do. I'd really like to move that line out of the clutch hole.

I also just purchased the Sunpro copper line install kit. So I guess I should take that back. Where do I get the other line that's on my oil pressure now but too old?

Be aware that if you decide to move temp. gauge line to a different hole in the firewall, it will have to be big enough to get the sending unit and fitting through. Most that I've seen will require at least 5/8"dia. or more.

Yeh, I thought that's why they put it thru the clutch hole but I really don't like it there. You know the clutch rod is rubbing it. Where do you guys run it thru? How bout a pic? What do I have to do to get it out of the engine block and is it true that if I remove it my gauge is trash? Would it still ruin it if I disconnected the gauge end first?

That's interesting - never have seen any hybrid plastic materials like John is talking about, only cheap plastic or copper line. I prefer the copper, I have never seen a copper line work harden and break - although I'm sure anything can happen.

Anything with a plastic coating for an oil pressure gauge is suspect IMO because the plastic does not hold a ferrule as well as a soft metal. When my plastic oil line failed it blew off the fitting and sprayed oil all over my inetrior. Have talked to others that have had the same problem with plastic oil lines.

To get your temp sensor out of the block just unscrew it from the block. When you take it out you will see the bulb that everyone is talking about. Once its out of the block you can reroute it.

Are there any decent oil pressure gauges that use an electric sender? It seems that would be the safest.

The dreaded double post.

Eric,

The water temp send unit has 2 nuts to unscrew. I unscrewed the outside one and all it did was slide down the tube. The big one in the head won't budge. So you're saying if I remove it, It won't damage my w/temp gauge? Thanks

Anyone else have an opinion on copper tubing for oil pressure? Maybe I should setup a poll. smile.gif

I think Autometer sells a braided ss oil line for
mech oil gauges, might be pricey though .
I saw one in Speedway Motors catalog in -3 or -4 AN with a 90 on one end & straight on the other end $ 18.99 for a 48" plus shipping. Me thinks it's better than copper or plastic. Aloha.

I'm not sure what you are talking about with the 2 nuts, but you need to unscrew the big one in the head. That's typical that it won't budge - they are tough sometimes.

Mine has a brass bushing screwed into the head and the temp sending unit screws into that. The temp sending using is about a 5/8" wrench, the bushing is takes about a 3/4" wrench.

The big one that screws into the head is a reducer bushing. When you unscrew the little one (the outer one) you should be able to remove the sending unit. It's probably just stuck - a little gentle persuasion should break it free if you have the nut completely removed. Be careful though, because if you fracture that tubing the gauge is toast.

I switched over to all electric autometer guages on my latest Camaro and have no complaints. It was also a cleaner install. Also no big holes in the firewall and no need to worry about lines breaking. Just my opinion.

Here's a pic of my w/temp send unit. Are you guys saying that anyway you remove the s/unit trashes the temp gauge?

http://images.cardomain.com/member_images/10/web/214000-214999/214503_114_full.jpg

Ramjam,
I was avoiding this post because, I didn't want to get into the copper vs. steel braided vs. plastic. It's almost like asking someone which carb is better or what cam to use (everyone has their opinion, you have to use what works for you).

In my opinion braided would be my first choice, copper second and I wouldn't even consider running plastic for the same reason Eric explained above. I have had and seen plastic lines fail (makes quite the mess). I have never had a copper line fail on me and have never heard of anyone that has. (I'll leave it at that).

You should be able to remove your water sending unit without damaging it. Hold the larger nut with a wrench and turn the smaller nut. If you try to remove the whole thing at once (the larger nut) you will twist your line and ruin it. once you have removed the small nut and line, you can then remove the adapter (larger nut). Hope that helps.

What I did to solve the plastic vs copper dilemma was replace everything with the Dakota Digital setup. Just install the sending units and wire the whole thing up. Even the speedo works off a sending unit, no cable. The system works great, a snap to install and in a 69 it looks pretty trick. But if your budget won't allow that, definately go copper. As for the temp sending unit you have, loosen the outer nut first and back it off. Do not allow the stem to twist. If it does, it will damage the unit. There is no need to remove the adapter unless it is cracked. That happened to me once and I could not figure out why coolant continued to seep out. A new one is cheap.

Autometer has electric gauges and sending units in at least three different styles. I have the Sport comp units and they work great. It`s alot easier and neater to route wires and you don`t have to worry about leaks in the car. Brent

Ram,
I dont think anyone has really answered your question about the water temp gauge line. On a mechanical gauge, which is what you have, the tube is made as part of the gauge. There is a special liquid in it that expands as the water heats up, and makes the gauge move. It is a sealed unit and cannot be removed from the gauge. If the tube breakes, the entire assembly goes in the trash.

However, like Royce said, you should be able to remove it from the head to route the tube through a different hole. Before you try though, I would really suggest that you buy a couple of "tube" wrenches. They are designed to go over the tube and hit on 5 of the six flats on the tube fitting. They make it a lot easier to remove without messing it up. A regular, open end, wrench will tend to "slip" on the soft brass fitting.

As far as which hole to use, you can always drill a new one wherever is convenient, then use a rubber grommet and some sealer to keep it from leaking.

Hope this helps,

Thank you all for the great posts. I should have made a new post since this became about water temp send unit.

I removed the copper sender from head it was just stuck. I lost about a 1-1/2 gallons of anti-freeze. I guess I'll just keep the old line it looks pretty good yet and worked when I took it apart. I re-routed it thru the speed cable hole I don't know why that wasn't used in the first place. So what sprays all over my interior if the line would break? Will the send unit seal right back up again?

I think you have two different issue confused. The line you removed is a capilary <sp> for the WATER temp gauge. If that breaks your gauge just stops working (nothing leakes).

If the plastic oil line that goes to your OIL pressure gauge breaks inside the car you will have OIL all over your interior. This is assuming you have a mechanical oil gauge and tubing that runs inside to the gauge.

Yes, you should be able to get it to seal again as long at the mating surface wasn't damaged.

Thanks again guys!! graemlins/thumbsup.gif