While checking under the hood, I noticed the engine coolant top hose (about 1-ft. long) from the coolant reservoir was missing a hose clamp to a union at front of eng compartment. Also noticed another hose with no clamp at left front top corner of engine, just below the plastic engine cover. All the other hose ends have clamps. Looks odd. Is this normal?
No, it's not normal.......I would take it to the dealer..let them put clamps where they belong. Maybe you got a car that was coming down the assembly line when Japan started shaking......assembler probably had something else on him mind.
Mine doesn't have a clamp either. Based upon what I'm seeing, I think this is normal. I'm thinking the non-clamped hose end of the union is a non-pressure overflow back to the reservoir. I don't see any evidence of seepage, leakage or discoloration because there's no clamp. I'm making a dealer call to verify, but I can get a hardware clip to put on it even if a clamp isn't needed; ie. piece of mind stuff.
I think I have at least one of the same missing clamps you describe. I've often wondered about it, but never been all that worried...
To be clear, I have a 2010 Prius, manuf. date of 05/09. And I have had no problem so far (20K miles). But I guess that the clamps SHOULD be installed, as they are installed on all the other hoses of the same type and on same connectors. Looks like they are "missing" to me.
It appears to be odd, but I think it is normal. If you look closely at the first connection you identified without the clamp, the hose appears to have been "heat-shrunk" onto the fitting and the fitting itself appears to have a different contour (grooved instead of flat) for that purpose. What appears odd is that the hose on the other end of the union has a clamp, but if you pull back the clamp on that connection you will see that the fitting is not grooved. The second hose connection without a clamp is a different type of hose and fitting, but the hose appears to have been molded to the pipe fitting. I would not worry about them based on the above, and also since I see no sign of leakage. It was probably done to combine fittings and hoses to reduce manufacturing and parts inventory costs.
Good thinking. All that you deduce may be right but that must complicate the assembly process. To keep the clamp-ends separate from the heat-shrink (maybe) ends. And then, years later, when a service shop across the world replaces a hose.........
+1 Good call about complicating assembly process. Toyota are you listening? We'd like to have the mfg savings passed on to us!
Its not a matter of deduction, rather a timeless principle of industrial engineering and production management that reducing parts and assembly steps simplifies the process, reduces cost and improves quality control. This particular hose will probably last the life of the car, but if it needs to be replaced it can be replaced with a hose and a clamp as it would if it had been originally clamped, or with a new hose and union assembly which may cost a couple bucks more than just a hose. Either way, it is nothing about which to worry or complain.
It's not complicated. Combining a hose and a union into one part and eliminating a clamp is a simplification. Savings which result from many such changes that lower the cost of production are passed on to the consumer in the form of a lower selling price. A lower selling price causes more units to be sold and more people who can afford to purchase an outstanding automobile.
In the centre of both pics are what I think are the hose ends in question, on ours: Does seem odd, considering that in both cases adjacent hose ends have clamps. You could put on a small screw type hose clamp, I think they're referred to has airplane clamps, just don't cinch it overly tight.
I don't have a 2010 to look at, but from the pictures, I would say that they are probably vacuum lines, and the part you refer to as a union is probably a check valve of some sort, and if others with the same car say that theirs are made the same way, then I wouldn't worry about it.
So if for example the other end of one the hoses is running into the coolant overflow bottle it doesn't mean that much?
Reality check: The so-called "union" is a coolant by-pass fitting as depicted in the attached. The other hose that is molded onto the pipe attached to the engine is a fuel vapor hose and is part of the emissions system. As far as puttting an unnecessary clamp on either of these two hoses, the old adage of "if it isn't broke, don't fix it" certainly applies here.
Considering so many cars have the same hose ends w/o clamps, I will relax. I will assume Toy. has a plan and that these are no-pressure hoses that will age gracefully. Thanks for all the input.
Prius Manual pg 12-7 section 1941: Any imperialist yankee dog who adds a clamp to any hose will suffer a total loss of warranty.
