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Discussion Starter · #1 · (Edited)
Couple months ago replaced the output flange seals on my 020 trans. Around this time afterwards my brakes began to require excessive pumping...3-5 rapid pumps to be even acceptable. Front pads (came w/ vehicle) were still good w/ over half their life left. Slide pins were grungy but those got cleaned. When depressing the caliper cups to reinstall pads they were STIFF! Before this braking all seemed to work good though. Haven't had the rear drums off yet.

FF a few weeks & been having to pump repeatedly to get a firm pedal. No change even w/ the vacuum line to the booster removed...which SHOULD make the brake pedal the next best thing to a rock...still a sponge. Could pump up & when holding could feel the pressure going away. I do point out that there are no brake fluid leaks...anywhere.

Suspecting possible internal leakage of the brake master...had this once before on another vehicle...replaced unit w/ another 6-port BENDIX unit. Pedal has marginal improvement...if any.

Brake hydraulic systems are a point I've rarely had to deal with...only came up once as an issue years ago on different vehicle (one mentioned had to replace the master). It possible my front calipers could be sticking in the extended position & when the pedal is raised they release the calipers are under some kind of vacuum instead of pressure that requires pumping to overcome?

If I have to stomp the brakes in a rush I might get 1 caliper to engage (tire drags) while the other will only slow. The rear lags behind also when this happens.
 

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I would start with the MC. As far as Calipers rebuilding them is a good thing, I couldn't believe on my 92 how much better the pedal did when I said rebuild time, which I also replaced the 2 front rubber hoses as well.
 

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Discussion Starter · #3 ·
Current MC is new Reman unit from AutoZone. It's their 4-port listing instead of 6 (truck has 4 lines + 2 pressure switches) but both looked identical w/ only difference being the 4 came with 2 plugs cost about $12-15 less...oddly.

The master did a good job of bleeding itself when filled w/ fluid when installing (wept out every orifice). Had to rush attaching lines into place. Pumped the hell out of the brakes until got no more bubbles coming out the reservoir. Probably should've bled the cylinders but didn't have to on the last MC job...just pump back up until got pressure back.
 

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Discussion Starter · #4 ·
Suggest possibly bleed the entire system & hope? I do that I might as well invest or setup a bleeder kit by using a tube on the nipple then fed into a bottle so on pedal release ideally it will intake fluid instead of air. Would also hope it's not perhaps the proportioning valve mounted to the rear axle causing or contributing to the issue.

Pretty unlikely I would think that what is supposed to be a "Remanufactured" unit fresh from the parts store should be giving me the same problem as the one I pulled.

I'd have settled for a rock hard pedal as long as it made the brakes WORK!
 

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Discussion Starter · #5 ·
Tried bleeding all 4 corners, this time with someone else in the cab. Pump up pedal 4-5 times then hold while I worked the bleeders.

Did the fronts 1st. Was told pedal was starting to firm though the passenger side took a couple more attempts. Though for some reason only when doing the driver's caliper did the fluid level drop significantly. Topped back off.

Then went to the back & after a few times finally got the rears to spit a stream that reached half way across the width of the axle when cracked loose...pedal held & tightened.

Went back to the front. Bled the driver's & was told the pedal was still firming up. Returned to the passenger & seems all progress lost.

Thoughts?

I don't actively recall the brakes on the truck ever being hard as a rock when engine was off...but they were firm. Did have the quirk that fairly often when brakes were depressed that the pedal would sometime stick near the floor & have to use my toe to pull it back up. But since the output seals were done is when the brake issue got BAD.

Have half a mind to pull the MC//Booster + rod out of the Jetta which is the later & easier to get type to do a conversion. I would have to use the brake switch off the Jetta on the truck since IT uses pressure switches (has 2) on the MC to operate the brake lights. I would just remove them & use those leads...of which one operates the dash light.
 

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Was fluid coming out of the passenger side caliper?
 

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Discussion Starter · #7 · (Edited)
Yes.
Entirely possible I just need to bleed the living hell (ie go through a full qt) out of everything?
The issue going is the same with the current Reman unit as the OEM unit BEFORE changing it.

EDIT: I think I know what a contributing culprit MIGHT be...possibly the rubber line on the passenger side. When hanging the calipers out of the way when doing the seals 1 of them (I think it was the passenger) which I wire hooked to the coilovers dropped sharply. Could have damaged the old rubber. Not enough to make me lose any fluid but enough to cause an air leak. Will replace those & go from there. Still probably get a hand pump bleeder to make the process smoother.
 

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look at a you tube for a DIY power bleeder. I have made one out of a 1 quart garden sprayer. works good makes bleeding a breeze. I would also take your bleeder nipple out and clean the hole in the caliper as well as the bleeder itself to make sure there isn't a pluggage. The hoses can delaminate internally they start acting as check valves and r-prevent the fluid from flowing correctly as well as the rubber softens and balloon as you are braking so there is fluid force reduction.

I used to buy reman units, then got 2 bad MC's in a row from Cardone on my Chrysler...I only do new now. or I rebuild my own.

You may have to deal with Autohausaz.com or vwheritage.com or werks34.de I suspect that a rebuild kit for these can't cost that much, as when I did my calipers IIRC it was like less than 10 bucks per caliper.
 

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Discussion Starter · #9 · (Edited)
Since my brake master is the BENDIX type the options are slim. No rebuild kits available or at the least are hard to come by. Has the wide pattern for the bolts. If was one of the narrower earlier HAYES units I could convert to the later models.

Just checked VWheritage & they only have the later types with the tube poking out the snout where the push rod goes. Can't use that w/o changing the push rod & booster. Same with PP. AutohausAZ has them for 200+. Critical item but that is far outside my budget.

Will try the hoses first & bleed. Since the issue only started up AFTER a certain repair that I had to dismount the calipers & move things around. On top of the issue not improving really in the least with the new unit though it's possible the unit was bum from the start. Like you said the hose might have separated internally.

EDIT: Checked out the DIY bleeders. Certainly looks more durable & practical than the cheaper bleeder types that suck instead of push. Would be inexpensive enough. For a DIY suck type I could see possibly using a 12V fuel pump. The pressure type would be more consistent though.
 

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I have used a Mighty-vac had to use Teflon Tape over the bleeders to prevent air coming in around the threads.
It worked ok, but then I figured to scour the inter web and found the DIY links to power bleeder builds.

The cost was about 5 bucks, the brake mc res cap was from a wrecking yard, I have one for all of my cars.

Green Red Gas Helmet Motor vehicle


Catch jar.
Drinkware Liquid Mason jar Food storage containers Fluid


Motor vehicle Gas Machine Automotive tire Auto part


Brake hose de-lamination internally.

Rectangle Font Parallel Brand Logo
 

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Discussion Starter · #11 · (Edited)
The passenger line I'm thinking DID kink up when it slipped from it's wire hook which easily could have caused internal separation even though it & the driver's are still pliable.
Thought I had another reservoir cap but nope & not about to butcher the cap on the SAR truck.

Got a couple replacement hoses coming. The trouble will be the line nuts that go into the flex line end. Bloody things go UP into them so just spraying PB blaster into it won't work so great. Figuring I'll have to resort to carefully using heat.

Will do the DIY pressure bleeder & keep some fluid in it so don't have to keep checking the reservoir to make bleeding all the air from a line easier.
 

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When going back, use teflon tape, it stops a lot of the corrosion.
 

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Discussion Starter · #13 ·
If done right & kept ONLY to the threads a small dab of aviation gasket sealer would also work. Have used it on bolt threads & it though it can make them firm it keeps them smooth & not stick since it never really quite dries. Tape works too.
Tomorrow will hit up the local HF for a cheap spray tank & HD for a cheap low-range pressure gauge. Can come up w/ the 1-1/4 pipe cap easily enough @ work.
 

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Discussion Starter · #14 · (Edited)
New soft lines in front. Brakes bled. Used the DIY with some success. The 1-1/4 pipe cap is too small & 1-1/2 is too big. Used double over piece of bicycle tube which helped but still leaks. Will have to use a section of rad hose or something & hose clamp it down. Ended up doing the finishing with someone in the cab.

Though the pedal is once again firm when bleeding & when not running but once running it seems back to square one. Pedal is very soft. A firm stop the driver's tire will work & leave skid marks in the dirt while the passenger keeps rolling.

Now for the first couple years of use the braking seemed fine. Stopped good. Though now that I think about it it always did require more pumping than the 84 2-door. Brake pedal seemed firm enough though sometimes the pedal would at time stick near the floor. I think now the 1st time I REALLY noticed the issue was about 4mo ago when I finally replaced the vac hose to the booster. One I was using had a bad habit of collapsing so the firm pedal I kept feeling was from lack of power boost.

I d/c'd the vac line & the brakes are now back more or less to how I remember them but still requires extra pumping to stop & a quick stop results in driver's front making skid marks & the other rolling.

Needless to say I'm irked. Can pump pedal up & hold but will slowly bleed down. No external leaks. Acts the same as before it was parked to do the MC.
 

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Discussion Starter · #15 ·
As briano said maybe another bum reman unit?
The caliper engages. Was suspecting the caliper but with corner off the ground & brakes depressed the wheel can't be turned (at least by hand).
This BENDIX 6-port unit is like the slightly later 4-port only units. DF line is in the F//L port & a brake switch in the rear port. PF line is in the R//R port w/ another switch (2 tied together & this is on the harness end) in the R//F. The 2 ports on the bottom go to the rear.

Have a mind to steal the 4-port off the 81 SAR pickup & HOPE it works since it has the same brake line layout. Only difference is I will have to install a brake switch in the cab for the pedal arm to operate.
OR
Pull the Rod//BB//MC from the Mk2 Jetta as a unit to then install. Trade out the front brake lines (which go to the front ports in the MC) & maybe the rear lines too if the ones in the truck lack the slack to make the necessary bends. Still need a switch in the cab for the lights.
 

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When you are bleeding the Calipers and the rear wheel cylinders you are getting good fluid flow?
I would think about getting a replacement (new) MC. And if you have your blower (heater) on full defrost, with the engine running, does it Quickly go to front when you place the lever in the full frontal? I never really noticed a braking issue on my 81 with the power assist, but I did notice that my a/c took quite a while to change from Defrost to Full front, and then it would go back to defrost occasionally, when is when I finally figured out my Vacuum Diaphragm was holed.
 

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Discussion Starter · #17 ·
When bleeding the calipers...with brakes pumped up & pedal held...consistently get solid jets of fluid. The rears will shoot half way across the width of the axle.

Truck heater wasn't hooked up when got it & the controls in the cab are the early type controlled entirely by cables (best kind IMO). The fan controller wiring is missing going to the knob. Was thinking of pulling the heater box but recently discovered when doing a hot wire test that the blower DOES work so may just keep it in. My vac pump is the centrifugal type.

Was about to get the form done to return my original misorder from RockAuto for the 1st MC intended to replace the one in the truck. Wasn't looking & it was an ATE 6-port unit w/ the narrow bolt pattern & the tube extension around the rod so wouldn't work.
Went to the Jetta & pulled the MC on it (the brakes on it work just fine) w/ the intent of getting ready for the conversion then remembered that the early ATE units will work with the non-BENDIX booster. It will bolt right up to the Mk2 booster & the rod inside fits even though it's smaller diameter than the later V ports from the Jetta. Then remembered someone doing a demo of the 2 types of master cylinders & how the early ATE ones were compatible with later stuff while the BENDIX weren't. Will just have to use the Jetta's booster & brake rod. Can keep my existing brake line setup & brake switches.

If it STILL doesn't work then either the MC is bad...different brand from different place...only out $34 or have issues elsewhere. THEN do the full Mk2 conversion which I know for a fact works. If it works using the ATE unit + the Mk2 booster//rod then can later convert to the Mk2 MC which would probably be an upgrade anyway.
 

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Discussion Starter · #18 ·
Got the Mk2 booster off but the rod is about 1-1/2in shorter than the one from the truck. The booster to firewall mount has studs but already have studs coming out of the firewall. Could punch studs out of the mount but looks like it would push the brake pedal too far out & the rod has no threaded accommodation for adjustment like the one that came off the truck. For this same reason can't just use the mount from the truck as the fork will be too far from the pedal...it can hook up but will have VERY limited travel.

Had heard that usually the conversion calls for pedal assy to be changed but that is an excessive amount of work. Easier to trim down the Mk2 rod & add a threaded extension then swap the pedal fork. A barrel nut w/ threads partially drilled out to slip just over the lip of the rod then welded on. Then take up the difference with some all thread OR just weld a bolt onto the end. Though the 1st way helps keep everything straight.

Got too dark to continue even with a flood light set up but will double check the length difference of the 2 brackets. If the Mk2 bracket is 1-1/2in shorter then can pop the studs & use it but then have to also re-bend the brake lines.
 

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Discussion Starter · #19 · (Edited)
Finally got the Mk2 booster rod modified. Thing was a hair over 10mm so had to bring down the width to a hair under 10mm for a die to bite. First die I tried despite saying 10x1.5 was NOT 10mm since wouldn't even start on a clean new 10mm bolt used to make the ends for the fork adjustment.

Well now BOTH front will leave skid marks after changing boosters to use the misordered ATE unite from RockAuto but still requires pumping a 2-3 times pumping. However can now get BOTH fronts to lock up which is an improvement but the rears will still roll & pedal will stay near the floor. Won't rise until start moving again. Now of course did what should have done from the start.

Also the pedal when pumped up & held it can be felt bleeding down.

With rear wheels off the ground they will free wheel for quite a while. Spun up then pedal pressed once& held they will each turn about 1 full rev before stopping & can still turn them with alot of resistance. Pulled drums & passenger shoes are about 1/2 while driver's is about 1/4 while also having that ! looking piece floating around & the skinny coil spring that attaches it to the front shoe reduced to a couple little pieces.

What else might be going on? Not the proportioning valve is it? Still had to get some help with the rest of the bleeding despite the DIY which helped alot...when pedal is worked I can see the armature on the valve moving around.
 

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Is that a weight sensing valve attached to the rear axle?
I have had to replace the brake adjuster as the step edges were worn smooth,
when was the last time that you replace the rear wheel cylinders, and possibly the rubber inter connect hoses.
 
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