Coolant Leak on carb / heater outlet hose, Occasional high idle / deiseling

[gbeyschau]

Hey ya'll first post here. I've had my '86 D50 (118K miles, G54B) for about a year now, got it from an older guy who bought it new. He seems to have kept up on maintenance, though the only receipts I found are for the PCV valve, tires and oil. The only issue I've had was a valve cover gasket leak that I fixed, until now:

The other day after about 30 mins of driving around town I got home and was about to turn it off when it started idling at about 2,000+RPM and when I turned it off it was dieseling. Couple days later it started and idled fine. I've since been reading the heck out of this forum trying to figure out what's going on.

I took the air cleaner off and saw that there is some coolant leaking from one of the bolts on top of the carb, as well as the T where the heater outlet hose goes into the engine and T's to the Carb (see pictures, used a pencil to point the specific carb bolt). No coolant leak anywhere else as far as I can tell, though the engine is a little dirty from the valve gasket leak. The coolant inlet and outlet hoses on the carb have some crusty buildup too. No idea if this is related to the high idle / dieseling.

The water pump seem to work fine. There's no white smoke from the exhaust or coolant in the oil (as far as I can tell) and the coolant looks clear and smells like coolant hah. Also no coolant smell in or out of the cab. I'm wondering if there is some debris or buildup in the cooling system clogging something up somewhere? Something funky maybe in the electric choke? Hoping it's not the head gasket or a cracked head :fingerscrossed

This will be the 1st vehicle I've done any kind of more diagnostic work on (I've done a radiator replacement/brakes/valve cover gasket/belts on other cars). Can anyone point me in the right direction? Should I drain the coolant and start pulling hoses off? Check the thermostat? Try to clean out the electric choke? What's on the other side of that bolt on the carb?

I'd like to do a Weber swap eventually (mainly to get rid of the overly complicated Mikuni) but if the head is toast I'll save my money.


Thanks for reading and apologies if this is too long winded!!

[SubGothius]

That bolt on the carb is a long hold-down bolt that just goes thru the carb body and screws into the intake manifold. A coolant leak there is odd, but there's a coolant passage from the manifold to the carb right next to that bolt hole, so perhaps the carb mounting gasket is leaking there, allowing coolant to creep up the bolt hole? Is that bolt even tight? I found one of those bolts was broken with the shaft just riding loose in its hole when I swapped to a Weber carb.

As for the leak at that coolant tee, could just be those hose clamps need tigtening, or maybe one of those hoses has developed a crack there and needs replacing, or maybe a pinhole leak in a hose is spraying onto it?

[FMS88]

on SubGothius's post. Drain a gallon of coolant before removing the carb otherwise you'll be mopping coolant out of the manifold. With the carb out of the way it'll be easier to access the tee and hoses. The tee may be corroded which has degraded the hose-to-tee seal causing the slight leak. Not a bad idea to replace the hoses, too, since if they're original, they're due.
By the way, welcome to the site.

[gbeyschau]

(Not sure if I already posted this reply, new to this forum style. Apologies if this is double posted)

Thanks SubGothius & FMS88! Looks like you're right. The tee -> carb hose has a split in it. I pulled the Carb bolt out and it was sticky covered in coolant + there's a coolant leak from the carb mounting gasket right by the intake -> carb coolant passage.

I also noticed the head of the hold down bolt next to the leaky one (towards the front of the carb, front driver side) was not seated against the spring washer but it felt tight. So I loosened it, it turns 360 with some resistance and then gets tight again. uh oh. I tightened it back up as much as I dare and it's still 1/8" from being seated again. Maybe it's bent?? Yeesh.

Any tips on the tight bolt? My first thought was angle grind the head off, pull the carb and investigate but if there's a less violent method I'm all ears. Would really hate to screw up the the threads in the manifold (no pun intended hah). If I cut the head off and remove the bolt, is it easy to find a replacement? Does the K610 Weber kit use that hole? I'm thinking if the threads are messed up it might be easier (cheaper?) to do the swap instead of finding a new Manifold? I haven't checked the junkyards around here and wouldn't really know where to start to buy a new one.

Thanks again, I appreciate the replies and everyone sharing there knowledge!!

[FMS88]

Try loosening the stubborn bolt a bit and hit with liberal amounts of penetrating oil so that it reaches the carb base. Work the bolt back and forth to see if it will gradually come out. If not cut of the head and lift off the carb. Using vice grips, try again to work it out. If serious galling is the issue, your only option may be to strip the hole. If that happens, you can try an oversize tap and bolt, but the four stock mount holes are needed for the Weber adapter, so replacing the manifold or installing a heli-coli insert might be a better approach if your planning a Weber conversion.

[SubGothius]

In my case that bolt had snapped off right at the end of the plain shank portion where the threads started, so there was a long enough threaded stub sticking out to hit with penetrant (Free All is my fave for this, stocked at any O'Reilly's), let soak overnight and tap with a hammer a few times now and then, then turned it loose with Vise-Grips. Cleaned up the threads in the manifold hole with a tap well enough to bolt down the Weber adapter. Used some Permatex thread-sealing compound as a light-duty thread locker on it just in case.

The fact your bolt turns at all is prolly a good sign it's only slightly galled, not stuck as badly as mine was at least.

[Havelthebonk]

Good luck this is what started me down the webber swapp route I'm almost done now hope it helps ..but as I understand the designing problem cone down to the stack carbs being way to much tech for there own good so what to do order a " stupid " carb I suggest webber 32-36 there's a kit under part number k614 my old d 50 had one but she got tee boned . If u want to keep it stock rebuild the carb and change pcv and thermostat when u reinstall the carb

[gbeyschau]

Woohoo! Got the bolt out, pulled the carb and got the K610 Weber kit (definitely a legit one), and am mid install. It's been smooth so far thanks to all the Weber swap threads on here. I've got a couple questions though:

I'm having a little trouble with routing the throttle cable (I got the DGEV BTW) The boomerang -> L-bracket thing bends the smaller sleeve quite a bit. I've attached a pic, maybe someone can tell me what, if anything, I've done wrong?

What do I do with the hoses that went to the old air cleaner? I'm assuming the one that comes out of the exhaust manifold is the EGR. Not sure what the one coming out of the back of the valve cover is.

I've got a Carbole electric pump I'm going to install. I've read the Wiki & some posts of yours, SubGothius, and I'm wondering what the benefit is of including a relay in the wiring of it? Any tips on a specific relay and oil pressure relay switch to buy?

Thanks again! Can't wait to get this puppy back on the road!

Throttle cable routing:



EGR?:



Valve cover -> air cleaner hose:

[SubGothius]

Looks like your pics went missing, but a pic would help w/ your cable question. I did remove the cable support bracket at the firewall above the exhaust manny to allow a smoother curve to the cable routing.

The smaller hose from the back of the valve cover to the stock airbox is a crankcase breather.

The big hose to the stock airbox is for secondary air induction, which supplies fresh air to the exhaust stream to help consume unburned hydrocarbons. Your K610 kit may have come with a couple large threaded plugs to eliminate the secondary air system entirely.

I just capped off the breather barb on the valve cover and plugged the secondary-air hose with a pair of Spectre Performance #3995 stainless-mesh breather filters like these:

https://www.ebay.com/itm/233552465713

[gbeyschau]

I haven't had much time to work on the truck lately, just now diving back in. I think I've got the throttle cable routing sorted, but I've included a picture in case I totally messed it up somehow.

I'm about to install and wire up the fuel pump but I want to make sure all my bases are covered. I've been reading the big Weber swap thread and your post here in particular:

http://www.mightyram50.net/vbulletin...ll=1#post70182

I'm not sure if there's a way to tell but do you know if either of these will work? They're available locally which makes things easier:

https://www.napaonline.com/en/p/ECHOP6626

https://www.napaonline.com/en/p/MPEOP6626SB


Otherwise my shopping list is:

https://www.amazon.com/gp/product/B00NWZ3TUI

https://www.amazon.com/gp/product/B0BGHL8FKV
(might need to splice some wire here and there but it shouldn't be a problem right?)


Lastly am I stupid to mount the fuel pump here? (see pics.) I've seen some other ideas on this forum but I don't have the tools to fabricate a mounting plate.

[gbeyschau]

Oh I don't think I mentioned in the previous post, RE: fuel pump mounting.

Would tapping threads into the frame also be a bad idea? I don't think I can get the bolts on to the nuts inside the frame there.

[pennyman1]

That pump is a pusher pump, and needs to be back at the tank for proper operation. It cannot draw the fuel from the tank.

[SubGothius]

You might see if you could bolt the pump to those vertical support members, or bolt a generic angle-iron type of bracket to the holes already there and then bolt the pump to that. I mounted mine to the support rail across the front of the fuel tank on my longbed, but I'm not sure if shortbeds have that.

As for that throttle cable routing, It might help to flip around that P-clamp bracket (if you can) that's mounted to the boomerang, so the cable housing passes thru it towards the firewall side rather than the nose side as you have it now.

Also, was there a threaded ferrule on the end of that cable housing that you removed? If so, put that back on if you can, as that should attach to the bracket on your carb, secured by a pair of nuts like so: