I took my series 1 (1961) out for a Sunday drive yesterday. About 7 miles into the drive, I felt like the car wasn’t accelerating as it should. I thought it might be paranoia and drove for another 3 before it became very noticeable that the car was dragging. I pulled over and opened the bonnet (bit of a pain in an OBL) and noticed smoke coming from both front wheels. There was actually a small flame in on the drivers side which I quickly snuffed out. Where the brake line connects into the caliper, the brake fluid was bubbling/boiling (see attached video). I let the car cool down and noticed the fluid continued to bubble for a decent period. I couldn’t move the car when I put it in neutral and tried to move it.
As things typically go, this was the one time I didn’t have tools with me but someone stopped and lent me a 10MM wrench. I loosened the brake line bolt (it was still hot and super hot outside ~93F) instead of the bleeder valve. It released the pressure and I was able to move the car. I left it open for a while to make sure that the pressure was fully relieved and lost some fluid. I tightened it back, but still elected to have the car towed home. Once at home, I was able to drive the car about 200 feet to my garage. The car stopped, but the pedal was spongy from losing fluid and air in the lines.
I haven’t yet checked the car to see if the calipers are stuck engaged but I suspect not. I’m considering putting new fluid in, bleeding the brakes and then trying it in my neighborhood.
I suspect that I either have a brake line or master cylinder issue but could it potentially be an isolated incident? I understand there is also a pressure valve at the end of the master cylinder that could be the culprit.
Any advice of other ideas on what could be the issue? If I do put new fluid do i only need to bleed the front two since there are two reservoirs? Also, I’m guessing that the current fluid is DOT3 since it boilded (my understanding is that sillicone doesn’t boil?)? I’ve seen a lot of debates on the fluid type that should be used but I’d prefer to stick with mfg recommendations unless something else is already in it.
Ok so when you received the pressure you could move the car…… so unlikely to be the actual calliper itself……but that level of heat may have damaged seals and also the rotors……it’s not often that smoke and flames come from callipers.
It’s likely something to do with the master cyl but I don’t know enough about the 3.8 setup to comment with any degree of sense about the working of links , and servos on this model .
Hi David the 3.8 brake set up is pretty simple ,as a minimum I would I would change the seals in the front calipers plus install new flex lines .Would not recommend bleeding and trying again .From what I have seen on here the 4.2 set up is more prone sticking ?
Regards Gerry 62 Ots Ontario Canada
Based on some info in your previous posts, I assume that this car is pretty new to you, and that you don’t have a lot of information about its recent service history. If so, I imagine that you don’t know whether the brakes have been serviced recently or not. If I were in your current situation, I would consider the recent experience of seized front calipers as a strong “nudge” to service the braking system before it fails in a much less safe manner than it did this time.
The fact that both front calipers seized would suggest a master cylinder problem of some sort. The symptoms you describe of the brakes being applied without pushing the pedal as the car warms up suggests that fluid is somehow trapped in the system and its expansion with heat causes the brakes to be applied. When the brake pedal is not applied, fluid should be free to return to the master cylinder from the brakes lines, and from there free to return to the fluid reservoir. If the master cylinder push rods are not properly adjusted, the valves in the 2 master cylinders may not allow fluid to return to the reservoirs. The adjustment procedure is described on page L.13 of the Service Manual.
I think David is spot on and it’s time to go through your entire brake system including replacement of the ‘rubber’ hoses to the calipers.
Cheers,
LLynn
As always the gurus are on the ball!! As a safety issue, during yr brake cylinder rebuild please use a grease gun to squeeze the piston from the cylinder…the use of compressed air leads to very dangarous missiles.
You are correct, I don’t know the car well and it is significantly different from any of my other cars.
I would tend to agree that it’s a good idea to service the entire system. I did want to clarify that I had been using the brakes during the drive, but not aggressively. I did have smoke coming from both rotors but I only relieved the pressure on the drivers side caliper and was able to move the car. I guessing that relieving on one caliper could have allowed relief in the other since the two fronts are tied to one reservoir?
I recently received the service manual so I will consult it as you suggested.
Don’t know if you could see the video in the link at the bottom of my post but i have hard lines into the calipers. The only place I see flexible lines/hoses is just underneath the brake reservoir.
I will guarantee that you have rubber lines connecting the wheels to the rest of the car. Follow the hard line and it must have a rubber line, otherwise the wheels can’t go up and down.
Well actually Citroen Deese used a hinge type arrangement and hard lines at the rear, that did, indeed go up and down. But I take your point Bill. You do need a flex line at the wheel to turn tho! David, perhaps you are looking at crossover lines at the caliper.
Fascinating, I’ve always been intrigued by Citroens. I recently learned I am majority French, maybe that explains something. I learn something new every day! Thanks for sharing.
Yeah, I guess that makes sense. I’ll get it up on the lift and give it a thorough look. I fully acknowledge I still have a lot to learn on these cars so I will follow your advice. Thanks!
One of the things to make sure you learn before you even put it on a lift is where you can safely put the lift pads. Plenty of threads out there on that topic and I’m not an expert, so I’d recommend doing a search.
The video of the boiling brake fluid percolating around the flare nut strikes me as an odd thing and potentially indicative of a poor or loose flare connection to/seating in the caliper. Intuitively I would have thought boiling brake fluid would have bulged a flexible brake line or burst a cylinder seal before the flare connection would leak. David, as part of your overhaul process, you might want to check all of the brake line/caliper connections.
