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Lately I've been noticing that the rear brakes on my 2000 GTV have been locking up when on an incline at a stop light. The car does not roll as it should when I release the brakes. Tonight I checked the e-brake and pumped on the pedal numerous times with the rear of the car on jack stands and everything releases back to normal as it should. Can this problem occur only when I've been driving for a while and occur with higher temperatures of brakes calipers and fluid?? Has anyone here on the BB experienced this problem?
 

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My '73 GTV is doing something similar except all four wheel drags so I suspect the brake m/c or the booster. Mine start to drag after a mile or so. Then, after a while they will release. I am researching this and Papajam has a good write up about the braek mc. In it he talks about the compensating port and how they compensate for the expansion of the fluid. If they are plugged the brakes can drag. You might want to look into it.
 

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Thanks for your comments Rich. My MC and booster are fine. Another BBer PM'ed me and told me that it could be that the rear rubber flex line could be pluged up. I'll have to check that.
 

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have you flushed and replaced the brake fluid? a friend had a problem like that and the fluid had absorbed water and expanded when hot.
cliff
 

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I'm about to do a fluid flush and while I normally would have used Dot 4 fluid, soothsayers here said to use Dot 3 cause 4 is not compatatble with the seals in the system. I don't know what you're using or for how long your fluid has been in there, but you might want to start out with a flush and see if anything changes (for the better).
 

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Discussion Starter #6
I actually changed the fluid just before the drive to the2004 Convention in New Hampshire. I used the original ATE dot 3 brake fluid. That was 3 years ago, but not to many miles were put on since then. I think I'll replace the fluid again for safety's sake. Thanks for your comments.
 

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Anthony,
So you only change the the brake fluid when you go to a convention? It's a good thing you change the oil more often :)
I have a Motive Power Bleeder if you want to borrow it.
 

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I'm about to do a fluid flush and while I normally would have used Dot 4 fluid, soothsayers here said to use Dot 3 cause 4 is not compatatble with the seals in the system.
Balderdash!!!!!!!!!!!!!!!

DOT 3, 4 & 5.1 brakefluids are all ether based and hygroscopic (they absorb moisture). The difference between the three types is the dry and wet boiling points. If a brake system is designed for use with DOT 3 fluid, the use of DOT 4 and/or DOT 5.1 brake fluid will do absolutely nothing to the seals. In fact, all three fluids are compatable with each other.
 

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Discussion Starter #9
Ken,
It seems to work out that way! Thanks for the offer on the power bleeder, I will let you know if I'll need it.
 

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Balderdash!!!!!!!!!!!!!!!

DOT 3, 4 & 5.1 brakefluids are all ether based and hygroscopic (they absorb moisture). The difference between the three types is the dry and wet boiling points. If a brake system is designed for use with DOT 3 fluid, the use of DOT 4 and/or DOT 5.1 brake fluid will do absolutely nothing to the seals. In fact, all three fluids are compatable with each other.

Hi Jim


Let me state catagorily that PJ was not one of the soothsayers that said this:). I will try to find the posting and link it.
 

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Hi Jim


Let me state catagorily that PJ was not one of the soothsayers that said this:). I will try to find the posting and link it.

starting at #42
specifically:
"As a trailing note on the DOT ratings, if your car was designed for a particular type of fluid (especially prior to the development of DOT 4 fluids), you should make every attempt to stick with that fluid! For example, if your car was delivered with DOT 3 fluid, the internal components of the system (seals, brake hoses, and fittings for example) were specifically designed and tested for compatibility with DOT 3. Because DOT 4 fluids contain a different chemical composition, the system may not necessarily react in a positive fashion to the borate esters floating around in the mix."

http://www.alfabb.com/bb/forums/showthread.php?t=41271&highlight=borate+esters&page=3
 

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starting at #42
specifically:
"As a trailing note on the DOT ratings, if your car was designed for a particular type of fluid (especially prior to the development of DOT 4 fluids), you should make every attempt to stick with that fluid! For example, if your car was delivered with DOT 3 fluid, the internal components of the system (seals, brake hoses, and fittings for example) were specifically designed and tested for compatibility with DOT 3. Because DOT 4 fluids contain a different chemical composition, the system may not necessarily react in a positive fashion to the borate esters floating around in the mix."

http://www.alfabb.com/bb/forums/showthread.php?t=41271&highlight=borate+esters&page=3
I am going to bet on the fluid change to cure the problem, all fluids will absorb water over time, all fluids must be bled at some point. It’s that simple
Unless before you changed back to the ATE DOT3 you where using DOT 4 and in this case I would point first to the MC as the seals are most likely SHOT ( or any rubber component) due to the DOT 4 chemical composition! Little different from DOT 3 as mentioned has borate esters floating in there to make a higher boiling point.,
3 years is a long time regardless of mileage. Should be changed every year or at least every 2 years. I suspect you have a build up of water in the system causing the brake lines or calipers to lock up.

Anyways
 

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Discussion Starter #14
Hi All,
Just to let you all know, the problem I was having is now cured. It wasn't the calipers, nor the MC or the brake fluid. The problems was a clogged rear flex line which may have been caused by not changing the fluid for 3 years. As I pumped on the braked pedal, it took about 4-5 pumps before I had any pressure to the rear calipers. I then removed the rear bleeding screws completely and no fluid came out at all.! So I basically had no rear brakes! So I disconnected the rear flex line where it is mounted to the hanging bracket and at that point the brake fluid was present and dripping. I removed the flex line, blew air through it, but no air came through the other end. I replaced the flex line and put in new ATE Dot 4 fluid, and I am now back on the road.
Thanks for all your help and advice guys.
 
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