Serviced brakes, now no brakes

Messages
3,646
Location
Worst Case, Ontario
Hello everyone, I serviced my brakes on sunday, everything went pretty smoothly other than a few things: 1. When I went to service the rears, I forgot that you need the brake caliper tool to retract the caliper piston. I tried using my Knipex Cobras to spin it, but it just kept spinning. I eventually rented the tool and used it on both. The left rear caliper was obviously sticking as it had a lot of corrosion on it from what I assume was extra heat, and the pads had much more wear than the other side, and worn unevenly as the outer pad had like 3mm left and the inner probably had 6-8. 2. When I finished, I jumped in and fired it up without thinking to pump the brakes back up like an idiot and the pedal went to the floor. I had no brakes at all and drove into the gate in my driveway, lol. Now I have no brakes. I initially thought that maybe I had damaged the seal in that stuck caliper from spinning it and it was leaking. I went to the yard this morning and picked up both right and left rear calipers with the intent to swap at least the rear left, as it was clearly toast. Both boots were pretty sticky when I retracted the pistons, the rear left dust boot moved around a lot and actually came out of the groove on the piston and possibly the caliper as well. When I reassembled it, it seemed to be OK. That's why I originally thought it was a caliper issue. I pulled it onto the street (almost crashed again) and left it there over night. This afternoon, I rolled it back down the driveway and found that I had some brakes but I had to pump a lot, which is a classic sign of a bad MC to me. I also didn't see any brake fluid leaking from the rear brake calipers when I moved it. The MC is two or three years old. Everyone knows not to push the pedal to the floor because it can tear the seals on an old MC. I'm not sure that there would be that much junk built up in there, because I've only put about 10k km on it since the MC was replaced by a shop in 2016 or 2017. I was under the impression that this would not cause the MC to fail instantly like it did to me. I've read that it is possible to damage the seals in the MC by pushing the pedal to the floor and the seals "rolling" over and not sealing anymore. Is this possible? Because I'm pretty sure that's what I did. What are the diagnonses for a bad MC? I'm sure there are tests I can perform before I go out and buy a new MC. A shop replaced my MC and booster because the brakes on my car would barely function when you first started the car. The pedal would be hard but the brakes would barely function which is really scary when you are trying to back out of a parking spot in a parking lot. I've never replaced a MC before but I am definitely going to try because I have a second vehicle that I can use in the meantime. I have line wrenches, but I need a MC bleed kit too, right? I'm also having trouble finding the correct MC for my car: 2003 Jetta 1.8 auto with DSC. Rockauto only differentiates between DSC and non-DSC models. I'm not sure If I can use the MC intended for manual trans models as it has a port for the clutch that I don't need. I was wondering if anyone knows if I can use any old MC for a MK4 or if I should go to a parts store and get one that is matched to my vin. Thanks.
 
Messages
2,224
Location
Lyndhurst NJ
You probably ruined the master by not doing shorter pumps with no pressure. I had this happen to a car I worked on and was able to bleed out all of the air thats probably trapped in the ABS pump. Try multiple bleeds with activating the pump to see if anyhting changes, if not it needs a master and bleed. Be warned, it took me 14 liters of DOT 4 to get all the air out of the car this happened to.
 
Messages
6,645
Location
Suburban Washington DC
Originally Posted by maxdustington
When I finished, I jumped in and fired it up without thinking to pump the brakes back up like an idiot and the pedal went to the floor. I had no brakes at all and drove into the gate in my driveway, lol.
You have a dual circuit brake system so that if one fails, you still have some braking power. If both failed I'm guessing you have air in the system so a flush and bleed would take care of it. BTW, your hand brake doesn't work?
 

maxdustington

Thread starter
Messages
3,646
Location
Worst Case, Ontario
Originally Posted by Audios
You probably ruined the master by not doing shorter pumps with no pressure. I had this happen to a car I worked on and was able to bleed out all of the air thats probably trapped in the ABS pump. Try multiple bleeds with activating the pump to see if anyhting changes, if not it needs a master and bleed. Be warned, it took me 14 liters of DOT 4 to get all the air out of the car this happened to.
Yikes, that makes me want to take it to a shop as I have no way of activating the ABS pump. Are they any cheap diag tools that I can get to activate the ABS pump? I've tried to use a USB adapter and a pirated copy of either VCDS or VAGCOM but I could never get them to work consistently. I'm definitely going to own future VWs so I'm not opposed to spending some money, but I don't think I really need pro level diag tools.
 

maxdustington

Thread starter
Messages
3,646
Location
Worst Case, Ontario
Originally Posted by atikovi
Originally Posted by maxdustington
When I finished, I jumped in and fired it up without thinking to pump the brakes back up like an idiot and the pedal went to the floor. I had no brakes at all and drove into the gate in my driveway, lol.
You have a dual circuit brake system so that if one fails, you still have some braking power. If both failed I'm guessing you have air in the system so a flush and bleed would take care of it. BTW, your hand brake doesn't work?
That's what I realized, if the rears were bad the fronts would still work. The handbrake worked a bit, but it could not stop the car. The rear brakes in this thing are pretty bad.
 

maxdustington

Thread starter
Messages
3,646
Location
Worst Case, Ontario
Originally Posted by mk378
Did the reservoir run dry? Is there fluid in it now?
MC is full, and I can push the pedal to the floor with the engine off if that means anything.
 
Messages
5,111
Location
Ohio
Originally Posted by maxdustington
MC is full, and I can push the pedal to the floor with the engine off if that means anything.
That's very interesting.... I'm sure that symptom tells someone with brake experience exactly what's wrong though.
 
Messages
7,482
Location
California
Originally Posted by maxdustington
The rear brakes in this thing are pretty bad.
I watched The Critic do a brake job on an A4-based Beetle, he had to replace both rear calipers and lines since the parking brake mechanism seemed to be jammed up. The brake fluid coming out was nasty. When he was resetting one of the calipers, a brake hose burst. Your Jetta has the same setup as any A-platform VW. However, master cylinders either work or don't even if they are leaking. The only way to find out is track down a brake pressure gauge and hook it up to the MC. Those are rare to find.
 
Messages
6,783
Location
Los Gatos, CA
If your master has fluid, clamp off the brake flex lines one at a time and apply brake. If the pedal holds, you found the bad path. Good luck. If you are not confident in your skills, get help. That's what I would do.
 

maxdustington

Thread starter
Messages
3,646
Location
Worst Case, Ontario
Originally Posted by atikovi
No annual state inspection?
Not in Ontario, cars only need to be inspected when they are transferred to a new owner. I think I am going to get a new MC and try to bleed. The only problem is the ABS pump. There's a gravel lot near my house that I can use to activate the ABS but I have a feeling that is going to be very tedious.
 
Messages
3,253
Location
USA
If you never opened a brake line or had all the fluid run out I don't see how air in the lines could be the culprit. There are third-party master cylinders that are almost DOA out of the box and will quit if you look at them funny. On a car with ABS you really need to consult the service manual about bleeding procedure. Generally though it would fall back to conventional braking if you pull the ABS fuse(s).
 

Kestas

Staff member
Messages
13,960
Location
The Motor City
Originally Posted by Audios
... it took me 14 liters of DOT 4 to get all the air out of the car this happened to.
Been there. There is no need to use 14 liters. After a while, just start recycling the clean fluid that comes out.
 

maxdustington

Thread starter
Messages
3,646
Location
Worst Case, Ontario
Originally Posted by mk378
If you never opened a brake line or had all the fluid run out I don't see how air in the lines could be the culprit. There are third-party master cylinders that are almost DOA out of the box and will quit if you look at them funny. On a car with ABS you really need to consult the service manual about bleeding procedure. Generally though it would fall back to conventional braking if you pull the ABS fuse(s).
I've had the same thoughts about the presence of air in the system. I've bled the brakes a few times on this car including an initial flush. Are there any brands of MC that are better then others?
 
Messages
6,783
Location
Los Gatos, CA
Originally Posted by maxdustington
Originally Posted by atikovi
No annual state inspection?
Not in Ontario, cars only need to be inspected when they are transferred to a new owner. I think I am going to get a new MC and try to bleed. The only problem is the ABS pump. There's a gravel lot near my house that I can use to activate the ABS but I have a feeling that is going to be very tedious.
Perhaps it is not a good idea to throw parts (aka $$) at it. Don't ask me how I know... Diagnose first. Good luck.
 

maxdustington

Thread starter
Messages
3,646
Location
Worst Case, Ontario
Originally Posted by nthach
Stick with OEM, which is ATE or TRW.
The car worth >$1000 and has a bunch of other problems. The only thing it has going for it is working A/C and being pretty.
 
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