1975 Transporter seems to be locking up

[a_walker]

I have a 1975 Transporter that I have spent the better half of 5 years trying to get on the road. I am not mechanically enclined so have had several different mechanics over the years do work on the van. Finally it is running. The last mechanic did a stellar job in getting the transmission rebuilt and getting the van so it actually would drive. In addition, the van has a rebuilt engine, new shocks, UV joints, brakes, etc.

So I am now having a problem in which if I drive (or run the van) for more than 20 or 30 minutes it seems to lose power. When you push the gas pedal it will crawl along at 8 miles an hour, almost as if it is being held back. If you continue this you will start to smell a burning smell. It has done this 3 times now and if I park the van and come back to it a couple of hours later it acts as if nothing is wrong and it drives normally.

At one point someone mentioned the brakes locking up and yesterday when it did this I touched the wheel rims and they did seem a little hot.

Does anyone have any ideas or thoughts?

Thanks in advance.

[Busdriver79]

Welcome to the Samba forums....You will need to change all of your flexible brake hoses...they swell internally and you can push brake fluid through them to the brakes, the brake return springs do not exert enough pressure to return the fluid to the master cylinder...change all four hoses and you should be fine...good luck....keep us posted.

[a_walker]

Thank you, Busdriver. So this is a common problem? Is it just because they are old and corroded? I'm not sure that this is something I would be confident doing myself. But I'll keep you posted on the progress.

[Wildthings]

If this was a brake problem the brakes should feel more than a little hot, they should be roasting hot. What happens when you quit trying to drive forward? Does it feel like the brakes are on and slowing the vehicle down? If all the brakes are quite hot and it feels like the brakes are on, then the problem is likely in the master cylinder. If the brake rod is just an iota too long it can cause all the brakes to drag.

Try pulling up on the brake pedal with your toe, does this make any difference?

[a_walker]

When the van is acting normally and I don't have my foot on the brake pedal or the gas pedal, the van moves forward on it's own volition. At a stop light I have to literally keep my foot on the brake pedal pretty strongly. But when it does this problem, if I am at a stop light and don't put my foot on the brake it doesn't budge (as if the brakes were on).

I just touched the outside of the rims for a moment yesteday because I hadn't zeroed in on this as a symptom. The rear were warm but the front were considerably hotter.

[Wildthings]

If more than one wheel is hot, then the problem is more likely something wrong with the master cylinder or booster, whereas a bad brake hose will affect only a single wheel. There is an adjustable rod between the master cylinder and the booster which may be too long which will cause the brakes to drag. If you push down on the brake pedal you should feel the pedal move easily for a 1/2" or so and then the force required to push the pedal should begin to go up quickly.

If the brake pedal isn't returning fully it will do this as well, try pulling up on the brake pedal. Iit should come all the way up on its own, but might not.

You could also have something in the master which is blocking a port and thus acting as a check valve.

It would be a good idea to change out your flex hoses anyway if they are more than 10 years old. They don't lasts forever and their failure might cause a catastrophe.

[GeorgeO.]

When you motor gets hot, vacuum lines tend to expand. That is where you might check first. If it was brakes, you would be able to run for the 20 or 30 minutes unless you purposely pulled the Emergency brake while you were traveling.

[a_walker]

Thanks, everyone. I am going to try to do a test run later this week and see if all four wheels are actually hot. And I will research those hoses. As far as master cylinder work, that is definitely something I would want to get someone who knows what they are doing for. I will post the solution when I find it.

[a_walker]

Hi Everyone,

I've finally solved this issue, after months and months. I am just posting in case someone else has the problem in the future.

As per advice on the forum the first thing I did was change the flexible brake hoses. That didn't work. Then we tried the calipers. That didn't work. Somewhere in all of this we realized that the brakes needed to be changed, as well as the brake booster. This still didn't solve the problems.

Finally, we changed the master cylinder (as WildThings) had suggested. That seems to have done the trick. This van saw water in Hurricane Katrina so pretty much everything underneath is (or is being) replaced. The master cylinder was a rusty, nasty mess inside.

Thanks to everyone's input.

So now on to the next problems...

[jtauxe]

That's great that you found the problem and fixed it, and in the process ended up with a refurbished brake system all the way. That's all good.

You had this other comment that caught my eye:

[a_walker]

Yes, it is an automatic transmission.

I may have spoken too soon, however. The problem I wrote about before seems fixed. But the last few days, the van doesn't seem to have power when starting out in first and maybe second gear. Going up a ramp on the interstate is really hard for it. The mechanic came and did more adjustments to the carborator, replaced the valve cover gaskets, changed out the spark plugs (the ones that were in the van were too short and he was suspicious of them). The mechanic now thinks the engine is going bad and suggested I order a rebuilt engine. This engine which is currently in the van was a rebuild, but the guy who did it moved away. I'm actually searching through the forum now to see if I can find any mention of a similar problem. Not sure if I should post a whole new topic about it. I hope there is a less costly solution.

[Wildthings]

You are saying it is a 1975 with a carburetor. US models for '75 came with a fuel injected 1800cc Type 4 engine. Is yours a US model or something different? Pictures would help here.

If the brakes were causing your problem they would be more than a little hot, they would be smoking hot and you could feel the heat from several feet away.

[a_walker]

I think I meant the master cylinder (not the carborator). To be clear, I am a total idiot on things mechanical. The mechanic replaced the master cylinder and that is when finally the brake ceasing up problem stopped. So to be clear that problem is solved.

But shortly after that problem was fixed the new problem has started. This is when I'm just starting out in first gear it's coughing and not getting power. I give more gas and it just doesn't speed up and sounds really loud. This might go over into second gear. By third gear it seems to work a little better. Also there is a small overpass nearby and trying to get over that the van barely chugs along no more than 10mph. The mechanic returned two times and replaced the valve gasket covers, new sparks and kept fine tuning (I think something with the idle). It had another issue the previous week of stalling at stoplights right after he did the master cylinder and he kept tweaking the idle and that worked itself out. But this getting no power issue, after continuing to mess with it, the mechanic said he thinks the engine is going bad and to get a rebuilt one. He was turning the flywheel thing that connects to alternator (also replaced) and said it didn't have compression on one of the turns. He also pointed to a little bit of smoke that was coming out of a metal tube sort of above the alternator.

Also, the exhaust system was replaced too (muffler, etc). It didn't have one previously and the mechanic just put a new one in. Not sure if that has anything to do with the equation.

I'm happy to take pictures of the engine. It's dark and pouring rain in New Orleans right now.

Thanks so much for your input.

[a_walker]

I actually was just looking at his texts and at one point he mentions coming to adjust the idle on the carburetor.

[Wildthings]

Yes pictures would really help.

You should also find your local aircooled VW club. There are probably people in the club just anxious to help you out.

[Tcash]

He was turning the flywheel thing that connects to alternator (also replaced) and said it didn't have compression on one of the turns.
Did he Adjust The Valves before he did this?

To start with, you need to have a complete tune up done.

Get a length of hose and put one end of the hose to your ear and with the other end listen for the loud noise. Where is it coming from.
It may have an exhaust leak? Listen around there.

Good Luck
Tcash

[a_walker]

Sorry, Tcash, I should have stated. As far as tuneup, he did replace spark plugs, did the valves...I don't believe he did a compression test.

He had done the valves before he was messing with the flywheel.

As far as the loud noises. When it's just idling and not driving, meaning when I'm at the back of the van on the exterior, it actually sounds really great. And when you reach in to rev the engine manually, it sounds great and sounds powerful. It's when you are actually in the driver's seat and starting to take off down the street, that's when the loss of power occurs.

You mention an exhaust leak. Could that have occurred when the new exhaust system was being put on, or a part of it is loose?

[Malokin Martin]

The whole scenario with mechanic X seems shady.

What you need, as mentioned above, is someone from your local club to look it over or get a second opinion from another shop. Tell them nothing about the first guys diagnosis.

Ps: Typically the rims aren't just "warm" when they're hanging up, they'll get SCREAMING hot eventually. Usually the paint will burn/smoke. It's not something that's a "maybe this is what's wrong" type deal.

[a_walker]

Here are a couple of pictures of the engine. I marked one of them with a yellow arrow (indicating where a little bit of smoke was coming from) and circled in green (where the mechanic was adjusting the three screws on the white plastic thing).

As far as the piping hot rims issue, they were amazingly hot. But that problem is totally solved and it's not locking up. The van has a whole other issue now.

The mechanic mentioned something about pistons or lacking compression. I'm trying to find someone else to give advice locally, but there aren't a lot of people here that work on these things. I wrote to the local chapter and have received no reply and their last get together was a long time ago (according to their website). So I'm still trying on that front.

[busdaddy]

It may help if we knew where "around here" is.

How long have you been running it with no tin surrounding the engine?, you shouldn't be able to see any road from above, your compression issue may be related to the lack of cooling your engine has been experiencing.
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