[george w]

I have to replace the brake hose leading to the right front caliper on an 89 Maserati/TC. I finally got the original hose off the hard line with some effort but the nut doesn't seem to mate up with the threads in the new brake hose fitting. The calipers are supposed to be the same as an 88 Daytona and all the hardware looks like the usual Chrysler hardware. My question is: Does anyone know if the brake line nuts/ fittings on the TC, or the Daytona are standard US or Metric ? They look like standard but I can't explain why the line won't bolt back up to the new hose. Are all brake fittings on this era Mopar, even a half breed like the TC, standard SAE, Metric or is only one standard used worldwide like on all sparkplugs having millimeter threads ?

Something has to explain why the nut just won't hook up. I bought a new premade brake line with new fittings already attached and it screws into the new hose with no effort wahtsoever. I wondering if I have a SAE hose and a metric nut on the TC's hard line.

The threads look to be of the same pitch and type as the caliper's bleeder screw.

 

[ImperialCrown]

They are metric. They may be Bubble-flare and not the standard Double-flare fitting which uses a different fitting nut.
The threads on the Bubble-flare nut start further back on the nut. Some aftermarket brake hoses can be the wrong style. Compare the line mating area of the new hose closely with that of the old hose.

double+vs+bubble+flare1201239518.jpg

 

[george w]

I'll check today. I "think" the line flare is a standard flare and the OEM nut still on the line has threads that start at the end. I suspect that the replacement hose I received may be SAE and if you're correct that the OEM nut is metric, then that's my problem. The new hose I bought were Raybestos from Rock Auto. They list a number of different brands of replacement hoses and some of the pictures on their site would appear that the same hose is sold under different brands. I bet my hose is wrong.

Maybe I should just order a set of hoses from Chrysler. The OEM hoses had steel fittings whereas the Raybestos boxed hoses have brass.

I'll take a new hose to the local parts store and see if the female end mates to a metric or SAE fitting.

 

[Bob Lincoln]

Daytonas use SAE brake line. It's 3/16" diameter, threads are 3/8-24, I believe.

Does the new flex hose screw into the caliper? If not, it's probably the wrong hose. If it does, the issue may be that it is not unusual to have some difficulty screwing the rigid line into the flex hose. I've found that the alignment of the threads is critical, it has to be just right in order for the threads to engage. Being off-axis very slightly will cause it to jam, or cross-thread, or not engage.

 

[george w]

Bob & Imperial Crown,

This has been an intresting exercize in frustration. Thanks to Imperial Crown for the link. I.C. noted that the hose to hard line fitting is metric. The flex hose to caliper is a banjo fitting and I have no problem on that end. I agree that the alignment in starting the fitting into the hose is critical, but I've done plenty of DIT brake line work before this little project. The brake line ion the TC is the usual double flare.

Here's what I found. I bought both metric and SAE brake line fittings at the parts store ( Advanced Auto Parts ) I also bought female to female union connectors of both SAE and metric. I also bought a premade SAE brake line that was preflared and equipped with the usual male brake line fittings at ench end. Intrestingly the SAE nut fits perfectly into the metric union. Equally as intresting, the metric fittings fit perfectly into the female to female SAE fitting. Go figure,They both tighten up normally. If there's a difference between the SAE and Metric fittings, the differences must be really slight.

But... only the metric female union would easily thread onto the hard ( metric thread ) factory brake line of the TC. I ended up taking the new "Raybestos" brake hose ( brass fittings ) and put it into a bench vise. I then threaded a steel metric male fitting into and out of the Raybestos hose until it threaded in freely. It took several in and out attempts to have it feel "right". At that point the TC's original line threaded into the new Raybestos hose and bottomed out as it should. I suspect that the Raybestos hose is slightly out of spec. The Rock Auto site offers a large variety of brands of these hoses. If the pictures are any indication it would lead one to believe that the same couple of hose manufacturers sell their product to a wide variety of parts resellers/repackagers.

Also intestingly the OEM TC hose had steel, not brass end fittings. I think I may try a set of lines by ConiSeal. According to the Rock Auto site the ConiSeal hose has plated steel end fittings.

 

[george w]

Update, but not quite solved yet. As far as I can tell the fitting nut on the hard brake line going into the brake hose is SAE. The line has the usual double flare. I bought two different brands of replacement hoses from Rock Auto which are clearly manufacturered by two different suppliers. Raybestos hoses which "look" most like the OEM hoses have brass fittings at both ends and ConiSeal, which have cad plated steel fittings and a sleeve type of protective sheath over part of the hose. The OEM and the Raybestos hoses have plastic 'protective" rings placed on the hose. Both sets of hoses accept only SAE male fittings.

The TC/Maserati is supposed to basically have the same brake hardware setup as the 88 Daytona with 4 wheel discs and I believe that the lines may be the same as well.