The Stovebolt Site Forums The Shop Area General Truck Talk for 30 yrs I've had the bleeding order wrong

I've always known you bleed the longest line first then the next longest line etc. Reading the online manual today it said Left rear first(I assume thats driver side), left front, right rear and right front-

I've been doing right rear(passenger), left rear, right front left front. In my mind I considered how far each was from the master cylinder..BUT the way the lines are layed out can fool you..was very surprised the the left front is longer than the right rear..I thought that was the shortest one..man no wonder it takes me days to bleed em.

Just wanted to post this incase I'm not the only dummy..

Keith

Never assume anything !!!! You have also assumed that by the left rear they ment from a position in the drivers seat. Not so fast, looking at the truck from the front the left rear is the farthest wheel cylinder from the master, then the right rear, and the left front and so on. The manual does not say in what position the writer considered the direction right and left,was he sitting in the drivers seat or was he standing in front of the truck/car? You have been doing it correct all these years. All the manuals that I have used and there have been way to many. You always start with the wheel cylinder that is the farthest from the master cylinder and work your way around the truck/car doing the cylinders in order from farthest to the closest the length of the lines don't really matter. I have been doing it this way for over 40 years and it has worked well to this point. Just my 2cents!!

I hate it when I thought I was wrong..but it turns out I'm right..But I still don't believe I was right.

The manual goes from rear to front-rear to front..I was doing the rears then the fronts...

I know the writer didn't explain if he was sitting in the truck or facing it-I think when you go to your local FLAPS to buy something-they consider drivers side as Left and the passenger right..so I went that way..

The front drivers side is deceiving--although you would think it's the closest wheel cyl to the master cyl..I believe it exits the master towards the rear of the truck, cuts over to the passenger side, turns towards the front of the truck..goes to a junction of 3 lines..then goes to the front passenger side cyl. Almost goes in a circle..

I'm gonna have climb under there tonight..

Thanks for the $02

Keith

When bleeding brakes, it is the cylinder that is the farthest from the MC by the length of the brake line; not as the crow flies.

Left and right are always from the drivers seat. AD trucks have the brake lines crossing over to the right (passenger)side and then heading towards each wheel. That's why the left side is farthest from the master (which is on the left side),
Scott

Ive been bleeding brakes for many years in the same fashion,always works OK for me.Passenger side rear,drivers side rear,Pass.side front and last drivers side front.Right or wrong in your book this gets the air out of the lines,and that is the purpose of bleeding the brakes.

It seems to me that the length of line would be instrumental. I believe the theory is that if you don't bleed the longest to shortest you can create a trap..a section with air that never gets bled out.

Actually this is good news-although I have always achieved a good pedal in the past 4-5 times I've needed to bleed, it's been murder. Maybe this is why.

Thanks,

Keith

It is the length of the lines that control, not the as Lonnie states 'as the crow flys'. This also changes in the AD lineup. I know that the pre 1950 trucks the left (driver's) side front line came for the right across the front crossmember. This changed at some point later on and went from the MC directly up the left frame rail.

Task Force also crosses from MC on left to the passenger side-after first going towards the back a foot or so..

Keith

Nifty 50,

Read my post again, as I stated it is the length of the line, not as the crow flies.

Not all years and models of the ADs are plumbed the same, therefore it is important that the lines are checked for length.

I think you've made your point that perfectly clear..

Thanks.

Keith

Slickriffs,
You were right in being wrong the first time. When replacing brakes last week I noticed, as stated above, that the brake line comes to the rear along the right (passenger's) side of the truck and then tees off to the rear brakes. The left brake is farther from the tee, and consequently farther from master cylinder. That is why this side needs to be bled first.

Are you guys talking about bleeding an empty system? I would think that if you're just changing the front, or just the rear wheel cylinders, the only air in the system will be at those wheels. Am I wrong?

Always best to bleed the entire system if it's been opened up, even if it's just on one end. Or even one wheel for that matter. Cheap insurance.
Off topic, sort of, on new cars, they use a diagonal split braking system. So that means that, depending on vehicle, you could have a sequence of RR-LF-LR-RF, and in some cases, having to bleed 1-4 bleeders on the ABS module.

Enjoying the responses..Even the most basic chores may be misunderstood..I learned something today..

Now..what about tomorrow?

Thanks all..some good stuff here..

Keith

Now, if you use a power bleeder, it doesn't really matter where you start, although farthest is still recommended,
Scott

Thanks Scott..Just ordered a relatively inexpensive power bleeder this afternoon..Can't hurt to keep the order right thou..

I've done it in the wrong order for many years..and eventualy did get good results..But there's always room for improvement..

Keith

Always!

Ive been doing them for 55 years & find it really doesn't make any difference.

It doesnt hurt to ensure that you flush out all the old fluid every year or ten..

I never thought it made any difference, ..........
but I never just changed one brake shoe without changing all of them, or at least both on the same end, front or rear......


never flushed out any brake fluid or changed transmission fluid in an automatic.......................a lot do though..

Just to finish this thread off-

I bought a pressure bleeder with a cap especially made for that old Stovebolt style master cylinder. I bought it on line from a company called Motive Product. I have no association with them.

Unpacked the unit..Hooked up a few things and tested it to hold pressure..then filled it with new DOT 3.Screwed the temporary cap in the master cylinder. Pumped it up to 15 lbs..and just put a clear hose (provided) on the wheel cyl bleeder..opened it with a wrench and watched til the fluid ran clear of bubbels. The first wheel alone(left rear) made a big difference. 20 minutes later the work was completed and I had a rock hard pedal.

Not say'n you can't do it the old way...I've done it that way for 40 years..But this is so convenient..especially when you work alone. I will expand on this in another thread..

One last thing..how this thread started..Bleeding longest to shortest..many of us accept that..I do..However my truck, with original lines, did not conform to the manual online..my 55 3/4 ton was..Longest:Left rear..then Right rear..Then Right front..then Left front

Keith

I have an antique (probably from the '30's) pressure bleeder, it is about 16" diameter and 8" high, has a pressure gauge on top and different ends that fit most master cylinders. Slickriffs got a modern version of this thing, mine still works like new, makes a no helper brake bleeding job simple and foolproof.

Call it Aussie inginuity, bush mechanics or whatever.......


........but I made up a spare master cap to which I drilled a hole and fitted a standard tubeless tyre valve.

To this I set my air inflator and regulator to a small 8 psi setting and hopped under the car to work the bleeders, only stopping occasionally to check the level in the master.

It's great not having to ask the missus "Foot down, hold, foot up" two thousand times!

LOL..My wife has done that a number of times..She's good at first..But then starts whining..I guess I can't blame her.

Keith

Keith, I looked at that bleeder from Motive Products, nice little set up for home, a little pricey for a plastic bottle, cap and hose but being from the old school, every thing looks out of line lately.
Say that mate, that might work but without a decent sized reservoir your going be bleeding off air and pulling that cap dozens of times to do a complete fluid change. The master cylinder reservoirs are really tiny.

Chevman, I got ya beat, I've got a pressure bleeder from the late 50's from a Chevy dealer that I was working at. It needed some repairs so they had just pitched it out. It's a metal housing with a rubber bladder that holds about a gallon of fluid. Pressure in the housing forces the bladder to collapse forcing fluid out. This keeps the fluid in a sealed container and out of contact with the air and moisture. The problem with it is, the rubber bladder rots away over the years and no replacements are available anymore.
The problem I see with the plastic bottle from Motive is the fluid is open to the air supply, moisture and atmosphere. Not the best environment for brake fluid, which is very hydroscopic, and has been the subject of discussion on several occasions here.
Denny Graham
Sandwich, IL

Motive suggests that brake fluid not be left in the unit.

The price of the Motive unit is a little more reasonable once you see the beautifully-machined thick-metal cap/cover for attachment to the master cylinder.

actually you don't leave the fluid in the tank after you use it

I don't get to check the board as often as I would like, but I need to back to the first page and my earlier post to make it clear. Better word choice and punctuation hopefully would have made it clear that I was agreeing with Lonnie. i.e. "not, as Lonnie correctly stated, as the crow flies."
Steve