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I know it sounds very strange but my brakes are locking up when the engine gets over 210 on a hot day. The underhood temp is very intense. I have already replaced my brake hoses with ss braided units, new reman calipers, dot 4 high temp fluid and new ss brake hardlines.
My corvette os a 1978 with a 427 sbc and electric fans. Unfortunately on a hot day with a/c and traffic I can't keep the Temps below 210 however it doesn't boil over.
But unfortunately my brakes end up locking solid after a few too many brake applications in traffic with the engine hot.
I just tried the trick with the washers between the master cylinder and booster however still no luck.
I know it sounds very strange but my brakes are locking up when the engine gets over 210 on a hot day. The underhood temp is very intense. I have already replaced my brake hoses with ss braided units, new reman calipers, dot 4 high temp fluid and new ss brake hardlines. My corvette os a 1978 with a 427 sbc and electric fans. Unfortunately on a hot day with a/c and traffic I can't keep the Temps below 210 however it doesn't boil over. But unfortunately my brakes end up locking solid after a few too many brake applications in traffic with the engine hot.
I just tried the trick with the washers between the master cylinder and booster however still no luck. Anybody else run into this problem?
Feels like it is all wheels, put perhaps the front ones more? Hard to tell since this only happens when in traffic and the engine at 210-215 and the transmission at about the same temp and I can start smelling atf.
I usually pull over, shut it off, open the hood and let it cool for 25 min then I'm on my way.
Only happens when I'm in traffic and thus don't have all that glorious airflow going through the bottom and heat out if the side gills.
I have longtube ceramic coated headers and a great cooling system but she still makes so much damn underhood heat.
I do have a line lock solenoid installed which I normally don't have power hooked up to but it is plumbed in to the front brakes. I have the brakes lines insulated, line lick solenoid as well but they still all get too hot to touch for more than a sec or 2.
Feels like it is all wheels, put perhaps the front ones more? Hard to tell since this only happens when in traffic and the engine at 210-215 and the transmission at about the same temp and I can start smelling atf.
I usually pull over, shut it off, open the hood and let it cool for 25 min then I'm on my way.
Only happens when I'm in traffic and thus don't have all that glorious airflow going through the bottom and heat out if the side gills.
I have longtube ceramic coated headers and a great cooling system but she still makes so much damn underhood heat.
I do have a line lock solenoid installed which I normally don't have power hooked up to but it is plumbed in to the front brakes. I have the brakes lines insulated, line lick solenoid as well but they still all get too hot to touch for more than a sec or 2.
I might be leaning towards weak MC seals. Should you chance it again, bring along a gallon or two of water. If they lock up, pull over and see if the brake MC is hot. If so slowly cool the MC with the water till it cools off and see if that helps. If so, confirmed.
I had something very similar happen to me this week. I got caught in I-95 traffic, and was crawling along for almost an hour in my wife's 79, L48 auto, no AC, stock clutch fan, Lars-tune, 180 degree thermostat. Partly sunny, black car, mid-day, 90 deg F. New-ish calipers and OEM-style brake hoses, old MC and booster. Did I leave anything out?
Anyway, the engine temp was rock solid at 185 or so (I was watching the whole time). My brake pedal got mushy. By the time I made it over to exit, I barely had brakes, and the "BRAKE" light would come on when I used them (indicating the combination proportioning valve was doing its thing, dunno if the front or the rear).
So, similar conditions, but the opposite result? I popped the hood, and the engine compartment was HOT. The coolest thing in there was the upper radiator hose.
I had an ice cream, found an alternate route, and finished the trip with no issues.
but with vacuum advance I'm probably closer to 19 degrees advance at idle
I have msd atomic efi controlling everything
it's definitely an underhood heat caused issue because on the open road, especially highway she will stay at 175-180 all day with the trans 10 degrees or more cooler than the engine
The engine has not overheated on me once but my trans has gotten to 250 and my brakes locked up solid where I couldn't even overpower them with applying the gas in drive.
I'm at about 27 degrees advance at idle, with the vac advance. I wonder what would have happened if I didn't have CAI.
Perhaps the difference is your braided brake lines (I have them in my other C3, but not this one) vs. my stock rubber ones. I'm really at a loss to explain how we repeated the same experiment, but with very different results.
Can you post a photo? I'm assuming your fans are mounted on the back of the rad, and therefore blow a lot of air under the car. Were they running at 100%, and at full blast?
Feels like it is all wheels, put perhaps the front ones more? Hard to tell since this only happens when in traffic and the engine at 210-215 and the transmission at about the same temp and I can start smelling atf.
I usually pull over, shut it off, open the hood and let it cool for 25 min then I'm on my way.
Only happens when I'm in traffic and thus don't have all that glorious airflow going through the bottom and heat out if the side gills.
I have longtube ceramic coated headers and a great cooling system but she still makes so much damn underhood heat.
I do have a line lock solenoid installed which I normally don't have power hooked up to but it is plumbed in to the front brakes. I have the brakes lines insulated, line lick solenoid as well but they still all get too hot to touch for more than a sec or 2.
Maybe somebody else can recall a story on this forum 8 or 9 yrs ago.
Same deal, brakes dragging, overheating, etc.
Someone figured out it was the braided lines that the owner insisted on using.
As I recall, the stainless covering of the brake hose makes it impossible to tell if there are defects. And when I say defects, i am referring to what they call a one-way valve in the hose. You would never see a bulge, but the hose swells and does not allow fluid to return to the MC.
In your opening paragraph, you state; SS Braided Units.
H-m-m-m-m-m-. You don't suppose . . . . . . . . . .
Maybe somebody else can recall a story on this forum 8 or 9 yrs ago.
Same deal, brakes dragging, overheating, etc.
Someone figured out it was the braided lines that the owner insisted on using.
As I recall, the stainless covering of the brake hose makes it impossible to tell if there are defects. And when I say defects, i am referring to what they call a one-way valve in the hose. You would never see a bulge, but the hose swells and does not allow fluid to return to the MC.
In your opening paragraph, you state; SS Braided Units.
H-m-m-m-m-m-. You don't suppose . . . . . . . . . .
Most quality SS braided lines have teflon hoses inside. Nothing to swell there.
Originally Posted by HeadsU.P.
Maybe somebody else can recall a story on this forum 8 or 9 yrs ago.
Same deal, brakes dragging, overheating, etc.
Someone figured out it was the braided lines that the owner insisted on using.
As I recall, the stainless covering of the brake hose makes it impossible to tell if there are defects. And when I say defects, i am referring to what they call a one-way valve in the hose. You would never see a bulge, but the hose swells and does not allow fluid to return to the MC.
In your opening paragraph, you state; SS Braided Units.
H-m-m-m-m-m-. You don't suppose . . . . . . . . . .
I know you put washers between booster and M/C but when brakes lock up again just loosen M/C from booster to see what happens . If brakes free up then either M/C or booster is at fault .Maybe seals in master are swelling too much or pin , in booster , isn`t adjusted correctly .
I know it sounds very strange but my brakes are locking up when the engine gets over 210 on a hot day. The underhood temp is very intense. I have already replaced my brake hoses with ss braided units, new reman calipers, dot 4 high temp fluid and new ss brake hardlines.
My corvette os a 1978 with a 427 sbc and electric fans. Unfortunately on a hot day with a/c and traffic I can't keep the Temps below 210 however it doesn't boil over.
But unfortunately my brakes end up locking solid after a few too many brake applications in traffic with the engine hot.
I just tried the trick with the washers between the master cylinder and booster however still no luck.
Anybody else run into this problem?
I'm your huckleberry. Mine is a 71 350 with E-Fans also. I have a very similar thread running in this section https://www.corvetteforum.com/forums...sing-help.html . I've done all of the things you've mentioned herein and they still locked on me the other day when we went for a cruise at the beach. I had to pull over and let it cool down for about half an hour, then the peddle went to the floor the first time I hit it, I had to pump it several times to get a good peddle back. I had changed the thermostat to a 180 and all was well until we went cruising the beach front. A friend told me he always ran a 160 in the many older Vetts he owned over the years. My next step is to fashion a heat shield for the M/C.
This is a first for me.
Only thing at this point that pops in my head is air/water in the system.
Either a loop somewhere it shouldn't be or
contaminated fluid not getting bled out.
The dprinter1 also brings in a bad m/c plus an area in the lines holding air water?
The whole idea about brake fluid is that it doesn't expand or boil.
Um, brake fluid can indeed boil which is why most will list that boiling point on the packaging.
"With a dry boiling point of 446-degrees Fahrenheit and wet boiling point of 311-degrees Fahrenheit, DOT 4 brake fluid is used in vehicles that are subject to high altitude, towing, or have ABS."
Originally Posted by calwldlife
This is a first for me.
Only thing at this point that pops in my head is air/water in the system.
Either a loop somewhere it shouldn't be or
contaminated fluid not getting bled out.
The dprinter1 also brings in a bad m/c plus an area in the lines holding air water?
The whole idea about brake fluid is that it doesn't expand or boil.
c3 corvette brakes locking up when engine hot
