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18 votes

What are these loops in the brake line for?

They are often times referred to as service loops. Their purpose is to allow some flexibility in the event the master cylinder has to be replaced, or a fitting needs to be repaired. It makes it easier ...
mikes's user avatar
  • 19.9k
18 votes
Accepted

What are these loops in the brake line for?

It is about vibration. The master cylinder and brake booster are mounted to the firewall; the firewall flexes. They move up and down significantly as the body jerks up and down when driven over bumps. ...
Fred Wilson's user avatar
  • 11.6k
10 votes
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Purpose of highlighted mirrors in trucks

They provide the driver with coverage of two significant blind spots. Especially in cities, there are numerous accidents with cyclists, pedestrians or even small cars being in that blind spot and ...
Rory Alsop's user avatar
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10 votes
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Wish to understand why non-stock vehicle alignment is an issue

Factory specs assume factory parts. Each modification you have made changes the angles at which the suspension operates so those angles no longer apply. This is especially true on truck lifts where a ...
finleyarcher's user avatar
9 votes
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Why do trucks have a plastic flap under the front bumper?

As @MooseLucifer said in the comment, these deflector strips are generally there for air deflection. They do two things - one, they change the air pressure under the car helping stability at speed, ...
Aaron Lavers's user avatar
  • 1,596
8 votes
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What is this connector on the rear bumper?

This is the access port for the tire iron so you can lower the spare tire from under the truck. Look at your Owner's Manual under "Vehicle Care," it will show you where on the truck to find your tire ...
tlhIngan's user avatar
  • 12.2k
8 votes

Headaches when driving older pickup truck

The shop vac can barely run because of the back pressure when hooked up the the tailpipe. If there is a severe exhaust restriction it could explain the presence of fumes in the cabin: if the engine ...
Zaid's user avatar
  • 39.2k
7 votes

Should I over- or under-inflate my tires when towing?

The conflicting advice is confusing to sort out, because the logic seems to have got the cause-and-effect connections wrong. So let's start again... The tires are the only part of the vehicle that is ...
alephzero's user avatar
  • 2,954
6 votes

Headaches when driving older pickup truck

Seeing as how the vehicle is over 20 years old, I'm doubting you are getting outgassing. That should have occurred a long time ago. If you drive with the window open to ensure fresh air flow, does the ...
Pᴀᴜʟsᴛᴇʀ2's user avatar
6 votes

Why do trucks have a plastic flap under the front bumper?

The more air allowed under a vehicle the greater affect this air will have on fuel economy. The lowered front air deflector will reduce the amount of air and thereby improve fuel economy. The large ...
Fred Wilson's user avatar
  • 11.6k
5 votes

E85 in my 1988 ford F-150 XLT Lariat

Whoa. Your 1988 F150 is TOTALLY NOT set up to run "flex fuel" E85. Please, don't do that. Just don't. Basically you are suggesting running your vehicle on 85% moonshine. Truth is, due to some ...
SteveRacer's user avatar
  • 12.4k
5 votes

How can I determine the turning profile of an articulated vehicle?

This is not a very easy topic. You are going to want to figure this stuff out for yourself and then do some testing to verify your design assumptions work the way you think they will. For the max ...
zipzit's user avatar
  • 6,559
5 votes

Why is there a "DO NOT PUSH" sign on the back of some trucks?

I like to share my experience in this DO NOT PUSH dilemma. It is really simple: You can damage the whole box since it was not designed to be pushed. It's just like a shoe box: you can stack one the ...
Nick Vladyka's user avatar
5 votes

What does this symbol on my dash mean? GMC W4500

That light indicates the Exhaust Brake feature is active and will work to slow the vehicle when your foot is taken off the accelerator. The picture is meant to be a throttle plate in the closed ...
JPhi1618's user avatar
  • 13.2k
4 votes

Headaches when driving older pickup truck

Since you qualified the exhaust system has no leaks, check the erg tube for leaks, also check the exhaust manifold gaskets if it has them, between manifold and cylinder head. Also check for oil leaks ...
Moab's user avatar
  • 7,990
4 votes
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Why Don't Medium Duty and Heavy Duty Trucks require Airbags?

Airbags protect the moving occupant against the sudden deceleration of the vehicle. Trucks usually hit objects that are lighter in mass. The truck's energy is transfered to the other vehicle, so the ...
John Canon's user avatar
4 votes

Should I over- or under-inflate my tires when towing?

I think the terms you're using - over-inflate and under-inflate - aren't the best descriptors. There's a maximum tire pressure, around 50 psi for many tires. Inflating past that PSI would be over-...
Dan Mantyla's user avatar
4 votes
Accepted

Tire chains appear to touch suspension components?

Chains, when fitted properly, should be uniformly tight and not have "knots" or "bulges" to catch on suspension or the inner wings. That said, I have heard many chains "clanking" on cars that have ...
Solar Mike's user avatar
  • 34.6k
4 votes
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Electrical question - solar panels and kill switches

I would look into setting up a relay controlled by the ACC or RUN circuit. When the coil in the relay is not energized the contacts would connect the panel to the battery but when you switch the ...
narkeleptk's user avatar
  • 3,780
3 votes

Engine noise and smoke while driving with low oil, no longer starts

It sounds like your engine may have seized. The thump and smoke from the starter sound like the starter is trying to turn the engine but can't. Starter motors are usually unfused, so if the motor can'...
dlu's user avatar
  • 14.5k
3 votes
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2003 Dodge Ram 1500 3.7 engine knock

The 3.7 is notorious for having a rocker arm fall off and or lifters collapsing. This is usually accompanied by a check engine light being illuminated. Use a stethoscope or a long screw driver and ...
Ben's user avatar
  • 10.7k
3 votes

Scania clutch issue with syncromesh gearbox

G'Day, The fact that you HAVE to pump the pedal a few times makes me ALMOST certain that the 'ServoMaster' unit INSIDE of the Bell Housing is knackered. At the release of the 4 Series in AUSTRALIA ...
LuKo2003's user avatar
3 votes

Oil Leaking after Oil Change...Seems Shady

Without pictures, it's impossible to diagnose the location of your oil leak. Here's some possibilities: The drain plug is not properly on. These don't need to be on tight to make a good seal, but ...
tlhIngan's user avatar
  • 12.2k
3 votes

Where to attach ball hitch on 1989 10ft former U-Haul truck?

The ball hitch needs to be properly connected to the chassis - the step, unless it is a structural member, will not be strong enough. If you can't recognize a suitable member then go to a garage / or ...
Solar Mike's user avatar
  • 34.6k
3 votes

What do I make a custom box truck body out of?

It depends how much money you want to spend on your truck and how reliable it should be on/ off road. If your body is heavy, you will need a better suspension. Plastic would be cheaper than aluminum ...
MightyV8Engine's user avatar
3 votes

Should I over- or under-inflate my tires when towing?

I had this same question, and while I mostly agree with alephzero's answer, I wanted to provide a way to actually account for the increase in tongue weight (the trailer's load on the vehicle). Let's ...
Drewster's user avatar
  • 286
3 votes

Manual transmission grinds shifting into 2nd gear, only when cold

You don't really give us much info about this except to say it was rebuilt 10 years ago. How many miles since then? What kind of service? There are two most likely causes: clutch and synchros. The ...
mongo's user avatar
  • 2,115
2 votes

1987 Dodge D150 High Idle and Dieseling

My first mechanic post. But were struggleing here many comments no answers. Maybe it doesn't apply to this vehicle. Dieseling run after shut off is sometimes caused by the vacuum switch on the air ...
danny117's user avatar
  • 197
2 votes

starter doesn't turn with ignition switch

Turns out if was the starter, I simply went to a junk yard pulled a starter out of the same kind of truck and it worked fine.
nwmcsween's user avatar
  • 131
2 votes

E85 in my 1988 ford F-150 XLT Lariat

The first thing to check is the fuel filter. The ethanol can dislodge dirt etc in the tank that's been sitting there, and will go into the filter. I've often found that when running e85 the first few ...
Aaron Lavers's user avatar
  • 1,596

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