1979 f250 issue
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1979 f250 issue
Hi this is my first time on here, I'm looking for some advice!
Anyway I picked up a 79 f250 about a month ago, it's been keeping me busy with body work. But now I'm starting to address the mechanical side.
My concern is safety right now before I start driving it around and here is why.
First off it's a 351, starts right up even after sitting in the previous owners yard for 2 years.
How ever when I apply the brakes it stalls the truck within seconds which is depressing. The seller told me it would be the power brake booster.
Has anyone had this issue before? All thoughts are appreciated!
Anyway I picked up a 79 f250 about a month ago, it's been keeping me busy with body work. But now I'm starting to address the mechanical side.
My concern is safety right now before I start driving it around and here is why.
First off it's a 351, starts right up even after sitting in the previous owners yard for 2 years.
How ever when I apply the brakes it stalls the truck within seconds which is depressing. The seller told me it would be the power brake booster.
Has anyone had this issue before? All thoughts are appreciated!
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It runs strong it definitely wants to move. I haven't gone far though.
I have a new booster in the garage, just been a matter of time to swap it out. Hopefully this weekend.
The pedal isn't soft to the touch
I have a new booster in the garage, just been a matter of time to swap it out. Hopefully this weekend.
The pedal isn't soft to the touch
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From: Knoxville, TN
Welcome to FTE and congratulations on the new truck!
Glad to hear you've got the priorities right - safety is always the first thing to address on any vehicle.
I would bet the seller was correct. The brake booster is probably bad and pressing on the brakes is creating a massive vacuum leak that kills the engine. There's really no other plausible way pressing on the brake pedal could kill the engine, but to test this, you can remove and plug the vacuum line that goes to the brake booster - you won't have power brakes, so be careful if you try to drive it anywhere like this as pedal effort will be very high, but if that keeps the truck from dying, you've verified the source of your problem.
My concern is safety right now before I start driving it around
How ever when I apply the brakes it stalls the truck within seconds which is depressing. The seller told me it would be the power brake booster.
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Thank you! So far I've put in new floors, a cab corner, and patching up the door jambs/roof. So far so good. Solid frame freshly polished.
Biggest thing it needs is bed sides. But one thing at a time!
Any suggested oil blends? One person mentioned a 50w-10.
Biggest thing it needs is bed sides. But one thing at a time!
Any suggested oil blends? One person mentioned a 50w-10.
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10w 30 is plenty, 50 would be a little heavy. Some people run 10 or 15 w 40 but thats for very high mileage engines like 200k+ Mine has 339k and I'm still running 10w30 with no issues, just got smoke on start up the other day but not bad.
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The advice to completely plug the vacuum line to the booster and try again sounds really good. Also to check/replace the check valve if questionable.
As far as oil, flat tappet cam engines like our dents benefit from higher EP additives (zinc) compared to current newer roller engines. You can add zinc (ZDDP) to conventional car oil or use a higher zinc oil to start with. I use Rotella T 15W40 diesel oil as it has enough zinc to start with and is readily available.
As far as oil, flat tappet cam engines like our dents benefit from higher EP additives (zinc) compared to current newer roller engines. You can add zinc (ZDDP) to conventional car oil or use a higher zinc oil to start with. I use Rotella T 15W40 diesel oil as it has enough zinc to start with and is readily available.
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Well the booster helped for sure. Fresh oil. And I adjusted the float on the carb. IT still stalls but not nearly as bad as before, mostly when it's still cold. Any who here is a little video, I reved it and threw it in gear. Different sounds to my ears. A normal thing in old cars? If you can pick up on something via sound I'll be sure to send out some e-high fives!
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It sounds different when you put it in gear because it has a load on it now 
BTW, I wouldn't suggest revving a cold motor that much, give it a little warning lol.
You're stalling issue could be a variety of things, but I'd start with the idle mixture screws.
BTW, I wouldn't suggest revving a cold motor that much, give it a little warning lol.
You're stalling issue could be a variety of things, but I'd start with the idle mixture screws.
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