WOW - jazz1 made the best suggestion. "Door flew open---". DO NOT drive this thing again until complete inspection. Many years ago, midnight tune of 3 carb 409 '59 Chev then a test drive. Throttle locked open, shut it off ( huge flames out exhaust - stick tran car ). Problem: screw driver to adjust carbs, left on carbs & fell down blocking them wide open. Forgot about that trip until reading this post.
Update: I took advantage of some time off work to do a little work on my '57 truck this week. Thanks for the suggestions and concerns. I want to update to hopefully save someone a similar problem in the future. After really getting under the truck and into the engine I found that the transmission brace on the crossmember was slightly loose and under braking and downshifting and the right conditions it was allowing the engine to shift to the side a little. I thought that was the end of it but when I started getting everything back in line and repaired I realized that the braided steel line that guides the throttle cable through the firewall to the carb came out of the alloy adjuster housing that bolts to the bracket and jammed itself against the housing….. causing the same effect as if I had stepped on the gas. Amazing how such a simple thing could cause so much chaos. Just wanted to post this so you guys could check your connections and make sure you don't have the same issue. Notice that the photos show the steel line as it was when I had my accident and after I removed it and slid the line back into the adjuster housing. I realize one of the experts that have posted on my thread will point out that the nut is too loose. I took the photo while I was taking it apart to show what had happened. Everything what tight on this end. The issue was down at the transmission crossmember. I will be replacing this before the truck hits the road again.
I was always told that going to throttle cable over linkage was a safety measure by the manufacturers. That short cable as installed has none of the safety benefits.
I disagree, I think the issue was a combination of things. Hind sight is 20/20 so there's no need to get into could haves, should haves and would haves. The lesson has been learned...I guess... so the real issue is properly correcting it and preventing anything like this from happening again. I have looked at your truck from previous posts and reading through this thread this is what I recommend. 1. Properly secure the engine and transmission. It looks like your engine is mounted from the front by some homemade mounts. If I'm seeing the picture right, some of that work looks questionable. You can mount one from the front, but front mounted engines usually had bell housing supports like Ford Trucks or used short iron manual transmissions like GM trucks. Simply put, a modern V8 with an aluminum cased automatic mounted on the extreme front and rear will never be stable....for long. There's too much length and too much stress on the mounts and transmission case. You need either a side engine mount cross member ( tube crossmembers available and are a easy install for these trucks) or support plates at the bell housing that bolts to the frame. You need to mount that engine transmission soundly and solidly. 2. Get rid of that short cable set up and install some proper linkage! Cable or mechanical is fine as long as it functions properly with some "give". The set up now needs to go in the trash, I think you have found where 70s Pontiac and 57 Chevy truck does not mix.....so correct it. 3. I've got to say something about neat work. I really do not care if the engine or the whole truck for that matter, looks like it came from the bottom of the Alabama River as long as the linkage, fuel lines, vacuum lines and wiring are done in a neat and clean professional manner. It makes all the difference. It's not just for looks. A clean installation not only looks good and professional but it helps you find potential problems. The same goes for brake lines, transmission lines, linkage and E brake linkage.
Observation: Your throttle cable is mounted in the bracket for the kickdown cable. It is designed to go thru a bracket that mounts to rear flange on carb. I see that it is in a solid position, but it displaces the kickdown.
That throttle cable is only going to do that again, it's to short. You need to replace it with a new one and how is it going through the firewall ? The firewall mount should look like that bracket mount, what's that rubber looking thing it's attached to ?
The truth is most people go into a state of tunnel vision in a situation like that. It is not a character flaw it is just the way most of us are wired. It can be overcome in the future by giving the situation some thought and maybe a little drill or two so that if the situation happens you have you don't have to think about it. It is like combat training so you don't succumb to the natural urge to jump up and run and get killed.
I took a ride or 2 like that in a 69 Chevy pickup that was missing the recall cable as well. The motor would rock up, pull the throttle wide open and drop it into low just before it sheared off the trans linkage and the alternator ate the rad hose. Luckily we were too young to notice what we were hitting. I second the above suggestions on looking at all your motor mounts and replacing or beefing them up as well as changing your throttle linkage. Add to that list changing your door latch mechanisms for something newer and stronger. That door popping open actually concerns me more than the wonky motor mounts. An engine falling out and hitting the pavement is annoying. You falling out and hitting the pavement is somewhat more significant.
At least you had brakes, I lost brakes on a 74 f150 in rush hour, coming up to a red light. I was so lucky, I did hit any one, went through a red light and ran it into a guard rail at about 10mph finally to stop it, funny thing when I went to test what happened- brakes were fine, put it down to a faulty booster, but never drove it again.
Yep…. like I previously stated I am replacing the throttle cable and linkage. I'm guessing 98% of us wouldn't have thought twice about that throttle cable by looking at it before this happened. Nonetheless I am going over the whole truck and double checking everything before it goes back on the road. I just spent this past weekend going over my '66 C10. And yes…this is the type of scenario I have gone over in my head 100 times before it happened. I have played these things over and over in my head including fires or a wheel falling off. I periodically look over at my fire extinguishers in my vehicles and think about the sequence if something happens. It probably took me 5 or so seconds to turn the key off while avoiding cars, closing my door and trying to put the truck in neutral but with my speed and drum brakes the whole event was probably 15 or 20 seconds until I got the truck stopped. Easy to tell someone they should have done things differently or offer advice on what to fix on their car after the fact but considering the only thing that DIDN'T happen was my truck catching on fire I think I came out ok. New style door latches and disc brakes are on the way. Thanks again for the positive vibes
Can't let this one go....there is no way a faulty boosted can cause no brakes....impossible!! Sorry, carry on now....
My drum brakes did some weird things too before… I would have brakes and then the next time I hit the brakes there was very little there until I pumped them. Then I would bleed the lines again and they worked fine
I gotta say it. Your truck was not road-worthy or safe, by any stretch of the imagination. I am glad it was not worse.
Things go wrong very quickly and a few seconds goes by before most anyone would react to what happened to you. Good that you're getting it sorted out.
When the booster goes it can be like no brakes. I had an OT car that the booster went bad and it did stop eventually but certainly not very well.
LOL they can't go that here. Traffic citations have to be written on the spot. So I hear about the truck and I hear about the beemers and the like but I have not yet heard about injuries?
When a booster goes bad and offers no assist, it will require a lot of pedal pressure to stop, but as I said it cannot cause no brakes.
Well if it wasn't the booster than it had to be the master. All I know had zero pressure and the pedal went to the floor, and I pumped it like crazy. When I checked it no leakage, and then I had normal pedal. Bad master?
Yep, a bad master can do that; work one minute, the next no brakes. Had that happen on a work vehicle, the brakes were 'funny' for a few days, then went to the floor once. They pumped right back up and seemed to be OK, so I went out on a service call. Came out after the call, no brakes at all. I was extremely lucky... leaving where I was entailed going down a fairly long, steep hill with lots of traffic and cross streets. Could have been a disaster....
A bypassing master does that. It spits the fluid back into the reservoir so there's no external leak.
If you have brakes , and then suddenly don't have brakes, then have them again, change the master cylinder, its bad. You will also want to look for brake line & wheel cylinder leaks. Faulty brakes do not "fix themselves", ever! If the brakes fail, and they are not repaired by replacing parts and making adjustments, they will fail again, probably pretty shortly. Gene
I daily drove my Rambler for 15 years, with school and low wage jobs, used tires and marginal factory brakes, that's why now I don't scrimp on safety stuff.
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