Brake Fluid Question

boodles

Well-known member
Joined
Dec 24, 2017
Location
Canada
TDI
2003 VW Jetta
Seems like I always need to ask questions after my family says they’ve repaired someing. Ugh.

Ok, sort of a long story. Sorry guys. I have an 03 Jetta that I bought last year and parked out at my parents place before I put plates on it. While it was there, they took it upon themselves to “fix it up”. One of the things they did was apparently flush the brake lines and fill it. Around last Christmas I had brake problems (the flashing light on braking/accelerating) and was told to just “top it off - there was probably an air bubble”. Me thinking nothing of it followed their directions, bought a bottle of DOT 3 and topped it off. Problem solved. Temporarily.

Around New Years I was driving in a bad storm and was nearly T-boned. I saved the situation by running the car into a snowbank. It has since been leaking brake fluid. Dealership wants $500 to fix and flush it, which I don’t have right now, and I don’t trust my family to touch it again.

I realized today it’s actually supposed to have Dot 4, so all this while I’ve been topping it off with Dot 3 everytime the light comes on...

I don’t know what I’m supposed to do now. Keep topping it off with Dot 3, switch to Dot 4? I won’t have $500 to get the work done on it until the fall. I literally just caught up on my rent so I wouldn’t get evicted, and I drive this car for 2 jobs.

Any advice greatly appreciated.
 

SoTxBill

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its not the base, its the additives!!
TDI
13 passatdsg 10 jetdsg, 09 jetdsg, 2006 jetdsg, 2001Jet, 96passat, 86jet, 81 jet, 78pickup all vw diesel.
wow.. how do you know the leak will not get bigger and you will end up killing 42 children on a school bus?



You dont know where its leaking??? master cyl? front or rear calipers or brake line?


If you cant afford to fix it, you cant afford to drive it a wreck it at the very least. You dont have any friends who are mechanically inclined? No private shops nearby who can fix it cheaper than the dealer?


Sorry, I cant really offer any more than to tell you your setting yourself up for major problems. May you should ride the bus. Good luck, you need it.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Yea, fix the leak, hopefully it'll cost less than $500. The brake system is not something you can just add to for fluid loss. If you have a leak you have a potential total failure.
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
DOT 3 and 4 and 5.1 are compatible. 4 Has a higher boiling point. I wouldn't worry about the mix as much as the leak.
 

Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Ok, first off, all the DOT rating numbers are the same save for the 5. 3,4,&5 are all the same, just slightly different in temp ratings etc... dot 3 is fine. the best IMHO is DOT 3 ATE gold, and blue, if you can find the blue now that its been banned due to the colour. Anyways, its really EASY to bleed your breaks and ill cost you a foot or 2 of hose from hardware store for a few bucks if not less, and a spare plastic bottle.
Find the leak, most likely a busted fitting or leaking rubber hose. All in all you can do this repair in your parking spot with a few tools. if you had to go buy a jack, stands, and some common tools for this with parts, your looking at maybe $50 bucks at harbor freight. Watch some youtube videos on how to do it and fix it yourself and save the money for your bills. Breaks are easy to work on for the most part. Good luck, for the time being just keep it topped off with cheep dot 3 from auto stores.

here is a great set of videos for you to watch.
https://www.youtube.com/watch?v=n1NvtUwfRJc
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Ok, first off, all the DOT rating numbers are the same save for the 5. 3,4,&5 are all the same, just slightly different in temp ratings etc... dot 3 is fine.
Nah. DOT 5 is Silicone and incompatible with 3, 4, and 5.1.
 

Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
woops, my mistake, i always get 5.1 and 5 confused. its hard to find dot 5 and 5.1 in auto stores anyways.
 

boodles

Well-known member
Joined
Dec 24, 2017
Location
Canada
TDI
2003 VW Jetta
Ok, if it was spewing brake fluid in all directions I obviously wouldn’t be driving it. It’s the tiniest slow leak which is why I can’t find it. I only have to add about 250 mls every 2 months, if that, probably less to be honest. I’m not going to half ass fix it just to hold it over when that’s exactly what this is doing. I’d rather just fix the whole thing in one bang and have the line flushed since it’s been exposed to ice and air for going on 7 months.
My brakes have never failed me, not that I use them excessively since it’s standard and I always shift down anyhow. And if they ever feel squishy the first thing I do is check the fluid level.
All I’m asking is if I should keep using dot 3 like I have been even though it calls for dot 4, or switch it? When I have the cash in likely September or October it will get fixed.
 

Ol'Rattler

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Location
PNA
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2006 BRM Jetta
Dot 3 can be mixed with with Dot 4 without harming your car. Most likely the leak only effect 2 brakes. It has what is called a Dual Diagonal Brake System which means a single leak will only effect 1/2 of the brakes. It is very unlikely you will suddenly loose all of your brakes and kill a bunch of school kids.

Dual Diagonal Brake System


Your master cylinder has 2 hydraulic circuits in it. One part is for the LF and R/R brakes and the other part is for the R/F and L/R brakes. Watch for which part of the reservoir is loosing fluid and by following the lines to what circuit is leaking to narrow down your search for leaks.

If the damage was done when you ran off the road you will have to put the car safely on jack stands and look for evidence of leaks underneath the car. Pay particular attention to the rubber flex lines.

Just one example of rubber flex lines (Yellow Arrow):


One thing that is extremely important to remember is that brake performance can have a drastic effect on safety which means that the sooner you fix known problems the better for everyone.
 
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boodles

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Joined
Dec 24, 2017
Location
Canada
TDI
2003 VW Jetta
I’m aware of this. There is never ever a puddle under the car, which is why I know it’s the smallest of leaks. It only looses fluid when I use them more frequently, so pretty much only downtown driving.

I’m fairly certain what happened is that I ran along a show bank that was sheeted with ice and it scraped the line causing damage somewhere. Unfortunately because I have to pump the brake for a long period to actually see the fluid loss, I can’t tell where. I can’t even just follow the line and look for a greesy area because the bottom of the car is not in pristine shape.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
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98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
get to cleaning the break lines. ill bet you that your rubber brake line by the caliper is leaking and only when it gets hot from the rotor.

that or your master cylinder is leaking fluid past the seal and its pooling up in the brake booster.
Is it a manual trans? possible that your slave clutch cylinder is leaking into the trans bell housing or on top of the transmission.
 

boodles

Well-known member
Joined
Dec 24, 2017
Location
Canada
TDI
2003 VW Jetta
get to cleaning the break lines. ill bet you that your rubber brake line by the caliper is leaking and only when it gets hot from the rotor.

that or your master cylinder is leaking fluid past the seal and its pooling up in the brake booster.
Is it a manual trans? possible that your slave clutch cylinder is leaking into the trans bell housing or on top of the transmission.

Yes it’s manual. Would that be affecting the clutch in any way? It’s been acting funny more recently - didn’t think they could be connected.
 

Vince Waldon

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Apr 25, 2009
Location
Edmonton AB Canada
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2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
Would that be affecting the clutch in any way? It’s been acting funny more recently - didn’t think they could be connected.
As it turns out clutch is hydraulic and uses the same brake fluid... from the same brake reservoir. :)
 

boodles

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Dec 24, 2017
Location
Canada
TDI
2003 VW Jetta
As it turns out clutch is hydraulic and uses the same brake fluid... from the same brake reservoir. :)

:confused:

Don’t know if it could be at all related but the car seems to have “Off days” about once every two weeks where reverse and first are just impossible. I’d say 13/14 days it’s perfectly fine, and then I’ll get one day where the car absolutely refuses to go into reverse and struggles big time in first gear. All other gears work perfect as normal. Family said it couldn’t be the clutch going because it’s so inconsistent. So just been ignoring it for now because the brake issue is more important and cheaper. :( Shoot me.

Icing on the cake it needs some work done on the fuel lines/injectors too ��

I bought the car really cheap but the people who owned it before me didn’t take care of it at all, did hardly any routine maintenance and I garuntee it’s been in more than one farmers field, but it’s fun to drive and I’m a little attached now.
 

Vince Waldon

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Edmonton AB Canada
TDI
2001 ALH Jetta, 2003 ALH Wagon, 2005 BEW Wagon
I’d say 13/14 days it’s perfectly fine, and then I’ll get one day where the car absolutely refuses to go into reverse and struggles big time in first gear. All other gears work perfect as normal.
First and reverse are the only two gears that really need the clutch to disengage all the way... so that's where slowly developing clutch problems tend to show themselves first.

Until you get your brake issues sorted (which will mean flushing both the brake and clutch systems and bleeding both of them thoroughly) it's tough to recommend thinking about the clutch in isolation.

Icing on the cake it needs some work done on the fuel lines/injectors too
Dunno what symptoms you're having... probably worth a separate thread when you get to it... but man oh man fuel lines/injectors on this engine are pretty bullet-proof and rarely need attention... might be something else going on instead. Worth being sure before you plunk down your hard-earned cash in that particular direction. :)
 
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Ol'Rattler

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Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Yes. A slow leak in the brake system will effect the clutch. Look on the side of the reservoir and you will see a hose tapped into the side of it. That is the fluid supply for the clutch.

Because of where the supply line taps in, if the brake reservoir gets more that an inch or so low, you start pumping air into the clutch circuit. I have no clue why they did it that way.

The white nipple looking thing in the picture is where the clutch supply hose attaches to the reservoir. If you keep the fluid level above that point, there is a very good chance the air will be purged back out, if not, you will have to bleed the clutch.
 
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Mike_04GolfTDI

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Richmond, BC, Canada
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Mine: 2019 Golf R DSG, Wife's: 2015 Golf Comfortline TDI
I wouldn't worry too much about using DOT 3 brake fluid. Apparently it is nearly meaningless.

Here's a DOT 3 that is good for 486 degrees and a DOT 4 that's good for 446 degrees.

http://www.canadiantire.ca/en/pdp/o...domestic-486-degrees-946-ml-0381913p.html#srp

http://www.canadiantire.ca/en/pdp/o...domestic-446-degrees-946-ml-0381916p.html#srp

Other brands have all sorts of other temperature ratings, so it's not like it's a standard or anything, apparently. Just don't mix anything with DOT 5, is all I know... (It's silicone based fluid and is not compatible with anything else)

Oh, and here's a DOT 3 that's good for 500 degrees, and it doesn't cost more.
http://www.canadiantire.ca/en/pdp/oem-dot-3-brake-fluid-ford-500-degrees-946ml-0381928p.html#srp
 

Mike_04GolfTDI

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Location
Richmond, BC, Canada
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Mine: 2019 Golf R DSG, Wife's: 2015 Golf Comfortline TDI
Other way around bud, we know what you meant though;)
Follow the links. You'll see that there are DOT 3 fluids with 486 and 500 degree ratings and then there's DOT 4 with only 446. Look at the printing on the bottles.

I know that DOT 4 is supposed to handle higher temperature than DOT 3, but in practice, it seems the temperature claims are all over the place.
 
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BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
The important thing is the chemical makeup and I believe they're very close and compatible. When my 99 was new I bought some DOT5 thinking it was the latest and greatest. DOT5 is pretty much straight silicone made for old cars with older rubber seals.
 

KLXD

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Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
I imagine if you went to the DOT specs for each one there would be a minimum boiling point requirement.

I wouldn't be surprised that a company selling both is only selling the older spec stuff to cater to people that feel they must have the "correct" stuff for their older cars and it's all actually DOT 4 or maybe even 5.1 now.

What cracks me up is Valvoline selling "synthetic" brake fluid. Is there a viable "natural" source of glycol?

Hey Rattler, I assume they put the clutch tap high so a failed clutch system wouldn't run the brakes out of fluid. Combining the reservoirs saved some money.
 
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Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
What trans code? do you know, chances are your shift tower is worn to a nub, bearing is bad, and the impossible to find (cant remember the part name or number) ball bearing nut on the side is recked, it will function but a funky clutch issue and or that will cause 1st and R to go out, you can adjust things but if its bad your either going to have 1st gear or 5th gear, sadly.
 

boodles

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Joined
Dec 24, 2017
Location
Canada
TDI
2003 VW Jetta
What trans code? do you know, chances are your shift tower is worn to a nub, bearing is bad, and the impossible to find (cant remember the part name or number) ball bearing nut on the side is recked, it will function but a funky clutch issue and or that will cause 1st and R to go out, you can adjust things but if its bad your either going to have 1st gear or 5th gear, sadly.
No codes.
 

Ol'Rattler

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Jul 3, 2007
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PNA
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2006 BRM Jetta
What cracks me up is Valvoline selling "synthetic" brake fluid. Is there a viable "natural" source of glycol?
Hey Rattler, I assume they put the clutch tap high so a failed clutch system wouldn't run the brakes out of fluid. Combining the reservoirs saved some money.
Next time you are in the parts store look in the organic section. Organic brake fluid will be on the shelf next to the organic Plutonium. :D

I have no problem with the brake reservoir being shared with the clutch. IMHO, It seems like a great idea to me. The tap could be 3/4" lower and a clutch circuit leak still couldn't run the brakes out of fluid. Wouldn't you agree?

Apparently, only being half German and not an engineer cripples my understand of the superior German engineering involved. The Welsh/Irish in me would just put a nice single malt in the reservoir whenever 1st and reverse have a hard time engaging and drink a toast to a job well done. :rolleyes:
 
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Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
No codes.
No, i mean what code is your trans, not what codes are showing on the ECU. as in, is your trans a O2J, O2A... etc.... The O2A is a pile of crap and parts are near impossible to find now. this is one reason i neglect mine.
 
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