Dogote

More info needed, scroll to the last post. Thanks. Hello everyone, My 1986 long bed 2.5 liter 4x4 Comanche with a 5 speed has an issue. It had all the symptoms of a bad clutch master cylinder. So I replaced the master and the slave together. It worked again, but it never seemed to have quite enough travel. It has an external slave BTW. There was no air in the system, but it would still catch a little between gears. It would be better if I double clutched it. I'd bleed it (and I know how to bleed stuff) and it would not have any air, and still be catchy between gears. The travel was never very good either. It engages pretty quick of the floor. Then, after sitting for a week or two, it had no pedal. I pumped it about 10 times and it came back, then totally failed on the way to my shop. When I bled it again, it was very hard to push in. Like the release arm was stuck, or maybe the throw out bearing was stuck on the shaft. I had a helper push the pedal for me today and as soon as it got pressure, something popped. Hard enough to shake the whole truck (I was under it) Now the pedal it solid, as in it feels like there is a block of wood under it. I tried to work the clutch release arm (slave removed) with a pry bar. I know it is hard as hell to move them by hand even with good leverage, but I got thhe arm to flex, and it had no movement at all. Like everything is seized solid in there. I was thinking the new master cylinder was bad from the start, and it may be. But, I think I need to also pull the transmission out tomorrow and see whats up in there. If I pull the transmission, I am putting in a new clutch, bearing, and front and rear seals. May as well, the labor I'll put into it is worth far more to me than the money I'll spend on the parts. I need to use this truck next week for some home improvement, and didn't want to have to deal with a new clutch. So if I have to, I am doing it right. ​Most of the clutch kits I see on Rock Auto have a hydraulic throw out bearing or whatever you call the internal slave. Mine has an external slave. Whats up with that? The Haynes manual shows early models have an external slave, later has the internal. What do I buy for a 1986? I still think the master I bought is a POS. Anyone know of good brand to buy? I'll spend more if it actually works. Anyone had this issue before? I think I am right, maybe there is something I am missing.

Great truck. I love my 2.5 with a 5 speed and it's nice to see others put time and effort into them too.

1986 MJ 2.5. Lots of miles but when I was putting the new head on, the cylinder walls looked decent, and the engine had reportedly been overhauled by the owner before the guy I bought it from. I have good compression, and it does not use much, if any, oil. I converted from the PCV type plastic valve cover the the aluminum cover. I routed the front line that comes out the side into the vacuum port at the bottom of the throttle body via the metal vacuum lines. It has a 2 mm restricter in the line because I used a auto parts store fitting with a larger hole. Its Sunday, and I live in a small town, I don't have, and couldn't get, a hose to connect the rear plastic elbow to anything. My plan was to run it into the metal lines, and hook the other end to the airbox. At first it blew LOTS of pressure out, and oil with it. I threw a PCV valve on it to hold the pressure in (yeah, I know, bad idea) and the it blew the other line off on a trip around the block. How much pressure should be there? Why would I be making so much pressure beside rings being shot? Good compression, no oil burned. But what else beside rings? BTW, everything it totally clean if not new. I have a feeling I am going to have to tear into the bottom end now. Damn it. No time to do this until winter and I really need this truck for summer projects.

The pressure not holding on a cranking test tells you nothing except the mechanic has a leaky compression gauge. There is a schrader valve in the hose of a compression tester. The cylinder wouldn't hold pressure anyways.

Thanks! I am able to see in your picture what I needed. I try to do pretty clean work, but it takes me a while to get stuff done. My job is maintaining an Airbus/Eurocopter EC135P1 used for Medevac. Everything gets done as clean as possible. I carry that habit over into my vehicles, but I end up driving myself nuts with it and spending too much time and money. But, I have also driven all over the USA, lot's of it on either back roads or dirt roads, some in bad conditions. Because of the extra care I put into my machines, I have never had a failure that left me stranded. The negative side of that is that I have spent a lot of money tossing usable parts in the garbage because they looked like they would fail soon. With aircraft, I have guides that tell me how long a part lasts, and lots of specs to justify keeping or tossing something. With cars, trucks, and motorcycles, gut feeling, educated guessing, and paranoia is all I have.

Those results are a cranking compression test, not a leak down. Leak down results look like: #1 80/75 #2 80/70 and so on. Usually you put 75 or 80 PSI in, and measure the amount that the cylinder will hold. While it's leaking, you can usually located where it leaks to. Valves should not leak at all, no air should get in the cooling system(blown head gasket,, cracked head., but rings will loose at least 4% (on a nearly new close tolerance engine like a modern European motorcycle) and as much as 10 % on a healthy cast iron engine. You can hear the air leaking if you pull the oil cap. If it's leaking 20 or more percent into the block, you may need rings. As far as cranking compression, your not doing bad. I have now idea what the "drops to xxx" means. Sounds like they don't understand how to do a leakdown test. Most car mechanics have never done one. I am an aircraft mechanic, it's all we do on piston aircraft engines. It's common in the motorcycle world too, at least for the trained shops. Your cranking pressures actually look okay. No two cylinders are going to give the exact same cranking pressure. I recently had a cracked head on my 2.5. It cranked 90 on the 4th cylinder and 120 on the 3rd. The other two were in the 150 something. I then did a leak down. 4 was leaking out the exhaust valve (pulled manifold to find that) Found out when I got the head off it was cracked. Good luck.

A work in progress. I'd be driving it by now, but my employer shipped me off to Florida for a few weeks.

Hello Everyone, I am getting the Comanche back together. New head installed, lots of other new parts. I'm not sure the old colant hoses were ever routed or hooked up right. I am installing all new hoses, coolant, heater, vacuum, everything pretty much. Can someone post a picture or two of their 2.5 Renix (mine is an '86) engine compartment showing the hose routing? I have searched this forum, NAXJA, and Google, and have not found what I need. In particular, I really want to see the hose that goes from the thermostat housing to the intake manifold, and the order the hoses go back on the heater valve. Should I get rid of the heater valve? I have read through a few threads, consensus is I should. I am hesitant to have the heater core putting out heat 100% of the time, but if the door on it is decent, it shouldn't be too bad. We have 4 seasons with lows in the -10's and highs in the 100+, and everything in between. (today it was 45 driving to work, it's 85 now) I'd really appreciate the help. David

I love my '86 2.5. Thumbs up to a nice 4 cylinder. Nice truck.

I've read up a little on swapping in later model stuff for more braking. I may do that since I noticed a big hole rusted in my booster. Has anyone just bought this set up: http://www.crownautomotive.net/product/RT31037.html If so, was it any good?

Flew too close to a thunderstorm in a company employee loaner plane. Tried to hide from the turbulence along a river in a deep canyon. That worked for a while then I needed to climb up and head towards where I was going. Ripped part of the tail off the plane. Scared the f*&K out me. I won't do that again. The tail breaking also caused all planes of it's make and model to be grounded until a fix was engineered to prevent the same thing from happening again. It took over 4 months. I worked for the company that built the plane, and was on the engineering team. Not a happy 4 months of work, and the more I learned, the more I knew how lucky I was to be alive.

Switch or stalk? The part that sticks out is just a stalk (Here is a picture of me holding both https://goo.gl/photos/bidFQhLUqR6iYyx36 ), it shouldn't matter except if you have delay wipers or not. Just cut off the cord. If the actual switch is bad (the stalk is there but your blinkers don't "click" to turn left/right) then you have to dig into the steering column. I've got a great .pdf for how to do that! Edit: The switch is the creme/white colored thingy with all the wires on it hanging out of the steering column in the pic. Just FYI. Your link didn't work for me, but I need the stalk, not the switch. Signals work, wipers work, but the part that makes the washer work is missing. If its the same and just wires, then I can make it work. I wonder if I can re-purpose the cruise on/off to run my driving lights? Through a relay, of course.

I don't need cruise on mine, but I need a column/wiper/turn signal switch. The cheaper ones all have cruise. Anyone know if I can use that switch on a non cruise truck? Sorry for the thread hi jack.

Aeromacchi, from Aeronautica Macchi. They built the Harley Sprint 350's and other great bikes. The factory in Varese Italy is in an old hangar on Lake Varese. It is pretty much where the first float planes were built, and where the plane that eventually morphed into the British Spitfire was produced. I was in that factory in 2007 and at the time they were building MV Agusta motorcycles there.

I just bought the Promaxx Head complete with valves and springs. I'll let you guys know how it works. I'm off to Pratt and Whitney school tomorrow for the new helicopter engines at work. The head should be waiting for me when I get home. $332.00 plus $40.00 to ship it. Not bad. The wrecking yard 100 miles away wanted $200 with no guarantee other than it came off a running engine. They said if I found it was unusable, I could trade it for another, after driving 100 miles each way. The machine shop runs about $250 to clean, inspect, and cut seats and install guides. $332 is a deal compared to that, and much less running around on my part. I have a lot of free time to do projects with the job I have. I am on call 24/7 though, and for me to go further than 1/2 hour from my helicopter base (or have a beer), I need to have a relief mechanic take over for me. Glad I don't have to take a day off to go get a junkyard head.

Anyone know anything about these? http://www.quadratec.com/products/51108_0001_07.htm?gclid=CjwKEAjw_7y4BRDykp3Hjqyt_y0SJACome3Tb_BhDmmFr7i9y_Tv3ANzbWhi0fkux5zLOJRobSXz8xoCVeXw_wcB For the price, a new head delivered to my house beats the junkyard head for $200 that's a 200 mile round trip to pick up.

No, not at all. The brass will embed in the aluminum and cause dissimilar metal corrosion. It will also make the aluminum black with the brass that rubbing off into it. The best thing is not to use any metal brushes, but at least the stainless resists wearing into the aluminum part if use very sparingly. Red 3M scotch brite works very well. Better than a brush for most stuff.

It really depends on what it is on and if the aluminum has any coatings on it. Japanese bikes almost always are clear coated or painted to look polished or cast. I work on a lot of early European bikes like Guzzi, Ducati, and BMW, as well as some British stuff. They all have uncoated cast or polished cases. I like to use mag wheel cleaner for unpainted wheels on the cast stuff. Spray it on and brush it with a stiff plastic brush, then wash it off. Phosphoric acid is the active ingredient and if you can get a bottle of it and dilute it, it's even better, but I have found that for most jobs you may as well just buy what walmart has. I like never dull on polished parts. It is a cotton wadding compound. It looks like fiberglass insulation, comes in a tin can. Rub it on, polish it off. Leaves a vintage looking patina, but makes it clean and shiny. A paste of baking soda works on everything. It really gets the stains out and can polish stuff to a great shine. It's also like .99 cents a box, so you can use a ton of it. Get a couple boxes. It will work with a rag or a brush depending on what you are doing. I have clean an entire WW2 fighter plane with it, and then Neverdull before. Came out like a mirror, but still looked 60 years old. DO NOT USE METAL BRUSHES ON ALUMINUM. Its so bad to do that it's borderline illegal to do on an aircraft. You will ruin the metal, even though the immediate short term results may be acceptable. With that said, you can use a CLEAN stainless tooth brush on small select spots to get really bad crap off, but be conservative with it and don't do it on anything polished.

I took my head into the machine shop to get a valve job. They cleaned it and found cracks around #2 and #3 cylinders valve seats. I won't be using that head. So now I am thinking I should just find another engine. 1. Anyone know a good source for a overhauled 2.5 engine? There's lots on the internet to choose from. Anyone bought one? 2. Whats the difference between the early 2.5's and the later 2.5's as far as the block and heads? Can I buy a later one and use it with my renix system? 3. Has anyone bought a MPI Cherokee and swapped everything over to a Renix? What will I gain if I do? 4. 4.0? I'm going to search the forums and read about others who have done it in a second. I have read something about the fire wall not being right to do it on some early 2.5's. My 1986 is probably one of those. How do I know? 5. I probably should just find a parts engine and build one nice one myself out of the 2. But I have so many other projects and this was never intended to be a big project. All I wanted was a little truck to drive around town and haul stuff like building materials. Not having it running puts a hold on other stuff, like insulating my shop and getting organic alpaca poop for the wife garden. I'm looking forward to the great advice and moral support of this forum. David

The two Triumphs are my buddy's. 1968 T100 Tiger and a 1970 something 250 Cub. The Ducati's and Guzzi's are mine. In the pictures you can see a Guzzi 500 Monza, a Guzzi 750 Ambassador frame, a Ducati 450 Desmo RT, a very custom Ducati Sport Classic 1000, and a Ducati Monster 800. Not in the pictures are a KTM 1190 Adventure R, a Ducati Multistrada 620, and 6 other pre-1970's Ducati's. My wife and I have had a bad bike habit for the 25 years we've been together. Of the bike mentioned, most of them are hers. These pictures only show half the shop/hangar. The metal wall in the center is coming down when my renters lease expires. The whole building is 105 feet long. There will be 3 or 4 airplanes/helicopters parked in here and my toys will be put away along the edges, or at home. I bought this with the intention of owning my own helicopter business, but then work got really interesting and I am holding off and taking things slow with getting going on my own for a few years.

Thank you. Believe it or not, it's a mess right now, and I am not all the way unpacked from moving. I need to insulate and drywall, as well as build a clean room with an office above.

Okay, here's my plan. I am going to get the head done. I was thinking of doing the valve seats myself, but I have a Nu-way and a Serdi carbide valve seat cutter set up. They are more geared to 5 angle valve jobs on racing motorcycles. I have done 100's of Ducati heads, 100's of BMW heads, and probably 50 KTM heads, but I think I would rather pay to have this head done since one ruined cutter from my set up (or having to buy a different size cutter) is as much as a complete head job from the machine shop. My oil pressure is good until the gauge gives up after 20 minutes of running (I have a new sender to install) and the cylinder walls are fine, plus it doesn't burn oil and the rest of the cylinders have minimal leak down past the rings. It will last through the summer and if I need to, I can overhaul at a later time. I may keep an eye out for a 2.5 on Craigslist, overhaul it, and then swap out the short block when it's done. At least by the time I am ready to swap in an overhauled short block, I will have a lot of other things done already and won't be messing with a ton of time consuming details. The master plan for my Comanche is: 2.5" (on a JK unlimited) RK brand coil springs up front Bilstien 5160 remote reservoir shocks from my JK Add a leaf and shackles in the back to raise it to match the front. 31x10.5x15 mud terrains. Better steering components, such as a heavy duty tie rod, but at the very least, all new rod ends and ball joints. I don't want it any more than what I would consider "lightly modified" I mainly want it to look cool, work a little better on forest roads, be able to haul a little more, and still be able to be returned to stock if I, or the next owner wants it that way. As I have time I'll make a pre-style bumper and a better rear bumper (currently has some weak tube bumper with a bent hitch receiver) I also want a rack over the bed. I've been drawing some and almost have a plan. I want it to look more expedition than construction. I'd like to be able to leave my Canoe or Kayak on top most of the summer. I live at Lake Chelan (Huge recreation lake) and work next to the Columbia river, . Last summer I left the Canoe on the truck using a Yakima roof bar on the cab and put the other end on the tail gate. It was nice to be able to hop in the truck and already have all my canoe gear in it. I'd like to have it level and be able to haul stuff with out pulling the canoe off. The paint looks good from 20 feet away, but the clear coat is pealing. I have seen a few internet examples of doing a very light wet sand, and then re-clearcoating paint with pleeing clear coat and sun fade. The results were not like a new paint job, but were pretty damn good and kept an original "patina" look. I may give that a try. Even in it's current state, people comment on it being a cool little truck. It's been a while since having an older truck or car to play with. I'm having fun so far, despite the mess I make with it on my nice white floor.

I really like my 1986 X 4x4, 5 speed, 2.5 Comanche. I had wanted one for quite a while when this one came along, and it's a rust free little truck. I have limped it along for the last year. I never have needed to drive it more than 5 or 10 miles a day, maybe once or twice a week. Perfect for a 30 year old truck, I'll never wear it out. I dealt with it not running great and leaking oil because I didn't have the time or space to work on it last year. Now that I am in my new shop (airplane hangar) I have some space. Time is still tough, but I am trying to spend as much time getting project done as possible right now. Now onto what this post is about. In trying to fix all my leaks, both vacuum and oil, I discovered my compression on the rear cylinder is 60 PSI cranking and 30/70 leak down. The exhaust valve is burnt a bit and it needs a valve job. The truck has 196K on it. Supposedly the engine was overhauled at some point not too long ago, but I doubt that. The cylinder walls are smooth, like really smooth, except for a single vertical score, barely distinguishable by finger nail micrometer. I investigate further tomorrow. I'm looking for input on my choices here. 1. First choice, yank the engine, but a 4.6 Cherokee off Craigslist and swap the engine and anything else I need into it. Positive= A bad @$$ comanche Negative= I bought this to use as cheap little classic truck. It won't be cheap to start swapping engines and I am not sure I want to spend the time. 2. Pull the engine, have it tanked and machined, install an over haul kit. Positive= A nice, reliable, stock 2.5 Comanche. Negative= Time 3. clean up the valves, throw the head back on and install some new gaskets and hoses. Positive= The cheapest and fastest route Negatives= It may need rings or mains at any time, won't be "trouble free" like a freshly overhauled engine. I am leaning towards option #3 just to get it done.