1975 Travco 270 no rear brakes

[Acesneights]

Title says it all. So I started in the back at the wheels. Had the wife step on the brakes with the rig on a jack and running. Nothing. I opened the bleeder on the wheel cylinders and got a few drips. Pedal feels hard. So I moved up to the rear Hydravac. Opened the bleeder. Nothing. Loosened up the brake line coming form the master cyl. A little came out. I moved up to the master. I loosened up the line on the master that supplys the rear brakes. Very little so I think the master is bad. I poked around a few Travco websites and the part #'s I found were outdated. I found that if you need to look up an M500 you need to use med duty/heavy duty category with Napa. They had a reMan for 177 or new for 316$ but it was questionable if it was the right one. Further poking brought me to Raybestos website and part#MC39013. Again had to look under med duty apps. Poked around on the web and average prics was about 316$. Then found it on RockAuto's website. 5 left... \nWith discount 97$. I hope it's the right one.....

[69210]

You don't need a new master cyl. \n\nYou need to bleed the brakes through the slave cylinders that are attached to backs of the brake boosters.\n\nBrake boosters being the big, round, odd things under the frame and just behind the driver's seat.\n\nBleeding through wheel cyl's is for normal brakes; Travcos don't have normal brakes.\n\nCheck the junction box on the rr axle, these are known to leak brake fluid.

[Acesneights]

I tried bleeding at the hydra vacs. I am not getting fluid from the master. I took the line off at the master and got no fluid.\nAlso looking down in the rear resevior or the master I saw debris so the system may need to be flushed as well but I am not getting any pressure from the master with the line disconnected and the pedal feels like it is pushing against fluid so I am thinking\nThe rear of the master is clogged or the plunger is stuck. Also i had pulled the breather line off the rear hydravac and fluid came out so that hydravac was shot anyway. I took a hydravac off a 1974 220 I have for parts. It was the same one and appears to be good so I put it on. New master will be here friday.....hoping its the right one..: )

[69210]

If the plunger and rubber m/c parts are rotted (sounds like), replace them.\n\nRebuild kits for old metal m/cylinders are available at NAPA thru their Dodge Brake catalog BSP-VI-05 or 07 or 09, by this time. I have the BSP-VI-05 catalog, lists every brake component. Have to wait 2-3 days, but waiting is preferable to getting the wrong OTC part.\n\nAlretta Brakes (google for addy) carries Travco parts and the owner is not an idiot, you can deal with him b/c he knows what he is talking about --unlike computer jockeys in parts stores.\n\nTake rubber lines off the frt end, as these suck shut with age, and replace. I found rubber brake lines at Car Quest, a fluke I believe. I am sure you know all this.\n\nCheck the lines between the brake booster (you have 1 or 2 brake boosters?) and their corresponding slave cylinders. Again, cannot get pressure bleeding thru regular brake bleeders or brake boosters, only thru slave cylinders. This cannot be stressed enough.\n\nI would, because I did, replace ALL metal brake lines beginning at m/cyl. \nI also replaced all 4 wheel cylinders, rubber lines and clamps. \nBrake lines are mostly straight, can you bend your own? I can, so plain steel lines from NAPA were adequate.\nI also replaced brass junction block in differential and lines leading to/from it. The junction block was difficult to find to size; I was told thread depth varies between Dodge medium-duty trucks. Took the old one to NAPA to match. \n\nI used almost a gallon of DOT 3, takes a LOT of brake fluid to flush a Travco's system. \nUse a 3/8 line wrench at the whl cylinders, only way to tighten properly.\nAlso, do not "bench bleed," 1 person pumps brake pedal, 2d person opens & closes bleeders.\n\nPB Blaster, NOT WD-40, on brake bleeders, let it sit 24 hrs, soak again if necessary.\nIf previous owner has been at the brakes, you may have to replace all bleeders as well.\n\nGood luck, hope it is the correct mas/cyl. Keep the old one to rebuild. Get with Geoff of Alretta Brake, he will not sell you "stuff" in a hit and miss fashion as will parts stores --including NAPA. NAPA is excellent if you know exactly which part you need (BSP-VI-05 catalog).\n\n\ntried bleeding at the hydra vacs. I am not getting fluid from the master. I took the line off at the master and got no fluid.\nAlso looking down in the rear resevior or the master I saw debris so the system may need to be flushed as well but I am not getting any pressure from the master with the line disconnected and the pedal feels like it is pushing against fluid so I am thinking\nThe rear of the master is clogged or the plunger is stuck. Also i had pulled the breather line off the rear hydravac and fluid came out so that hydravac was shot anyway. I took a hydravac off a 1974 220 I have for parts. It was the same one and appears to be good so I put it on. New master will be here friday

[Acesneights]

Thanks, I will post up if the Raybestos one is correct. I should have it Friday. If not I will call Alretta. I posted a link to his site in the parts stickys. I have dual Hydravacs. 1975 Seems to be an odd year as it could also be Hydraboost form what I read. \nYes I can make my own brake lines. I have a ISO Double Flare Brake line kit/tool\nThe master had the wrong cover on it that someone tried to make fit so who knows. I see alot of hack work on this thing so far. I was going to leave the steel lines as they looked good and may have been replaced. The rubber lines, I was going to take down to the Parker Store and have made but if they can be bought premade that would surely be cheaper.\nBTW Feel free to post any links pertinent to Travcos. even if it's a Travco owner website. I hope to get as much info here in one place .

[69210]

You have knowledge plus tools, you will be fine.\n\n1975 may be the year on your title, but your chassis could easily be a '74, possibly a '73.\nChasses were built, parked, left to wait until an order for a specific coach came through. Travcos were not built "to order," neither were they mass-produced. Shortys like 210 & 220, however, were usually lower-end and built with specific options or lack of.\n\nA 1975 270 can have a chassis older than the coach by 1 year or even 2, be alert to this.\nOnly way to be certain is by doing the work yourself and checking actual parts from your Travco against the NAPA or Alretta catalog illustrations.\n\nGood luck. I wait to hear.

[Acesneights]

Thanks. That actually makes alot of sense . That is why the book calls out differnt masters for the 75. I went with the one specified for the 74-75. I "think" that will be the correct one. AFAIK 73 was the last year of front Drums. feel free to correct any of this if I got it wrong.

[69210]

Sure thing.\nCan you return if it is wrong m/cyl? \n\nDrums and discs. 1973 was the "industry-wide" introduction of frt discs on passenger vehicles and light trucks, not medium and heavy-duty trucks. Reasoning was that "most" vehicles on the roads were passenger vehicles or light-duty (1/2 and 1/4-ton) trucks.\n\nHowever, 1/2-ton trucks could be ordered with 4-wheel drums and 3/4+ came equipped w/drums.\n\nDrums, if adjusted properly and if the brake pistons are functioning, are more economically feasible than discs. Also, a 'swap' to disc brakes requires changing axle spindles which is not a job for the faint-hearted shade-tree mechanic.\n\nBrake linings were traditionally made from asbestos (hence "Raybestos").\nTrain brakes are still lines with asbestos.\n\nBy 73, the EPA had finally determined, although it was known in the 30's, that asbestos dust is a carcinogen and banned the use of asbestos for brake manufacture, so the Big Three switched. Disc pads are made of composite-I-don't-know.\n\n\n\n\n"Thanks. That actually makes a lot of sense . That is why the book calls out different masters for the 75. I went with the one specified for the 74-75. I "think" that will be the correct one. AFAIK 73 was the last year of front Drums. feel free to correct any of this if I got it wrong."

[Acesneights]

Yeah rockauto is pretty easy to deal with. That other place is actually not that far from me.

[Acesneights]

master came today \nVery Excited. It looks right, It's made in USA and was only 97$. if it fits I may buy a spare...